Absurdity of taught mechanics when firing rockets down - evidence of magic powder.

[Dave]

Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.

Consider this setup- a falling body which can fire a rocket for a
distance of five meters to double the acceleration due to gravity of
10m/s^2 t0 20m/s^2

Also have the standard equations of F=ma (force =mass x acceleration)
and energy = force x distance

If fired at the start of a drop the five meters takes a lot longer than
if fired towards the end of a 60m drop. This is because the falling
body is already going faster. Yet, with energy = force x distance, the
lower down you are when the rocket is ignited, the less powder you need
because the 5m drop doesn't take as long, hence you need less and less
for the same energy (force x distance) so it becomes more and more magic.

Calculated added energy is force x distance.
Obviously the added energy is related to the burn time.

What is taught is clearly not right, since the energy added is more like
force x time. (amount of powder burnt). Or maybe I'm completely wrong
and and misreading my data book which says
FORCE= MLT^-2 (dimensions of MASS*LENGTH/(TIME*TIME))
ENERGY = ML^2T^-2 (dimensions of MASS*LENGTH*LENGTH/(TIME*TIME))

The politics angle is that most kids give up on physics education, and I
have to say I don't blame them, because what is taught doesn't add up.
See previous posts since Dec 2022. Teaching at universities is generally
abysmal, and most students, like the lecturers don't really understand
it and learn enough to get a grade by turning the handle.

[Jim Pennino]

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.

Absurd perhaps to a marginally educated crackpot that doesn't understand
things like analytical geometry, slopes, and basic calculus, but the
rest of the world has found no issues* with Newton's laws of motion in
over 300 years.

If you ever perform an actual experiment, that is something real with
actual measurements, that shows Newton's laws of motion are incorrect,
you can start planning on how you will spend your Nobel Prize money.

<snip remaining puerile babble>

* Assuming of course non-relativistic speeds.

[Dave]

Post by Jim Pennino

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.

Absurd perhaps to a marginally educated crackpot that doesn't understand
things like analytical geometry, slopes, and basic calculus, but the
rest of the world has found no issues* with Newton's laws of motion in
over 300 years.
If you ever perform an actual experiment, that is something real with
actual measurements, that shows Newton's laws of motion are incorrect,
you can start planning on how you will spend your Nobel Prize money.

Can't attack the argument, go for the person, like a bad soccer player.

I saw that the BBC has an interest in basics - they got a presenter to
go the biggest NASA vacuum chamber and drop a feather and a bowling
ball. Bit disappointed they didn't go the top and drop against a meter
measure. Still think acceleration from free fall is better in m/s per
meter of descent, and basically momentum and kinetic energy are the
same. More exciting possibility exist may exist with negative inertial
mass - but on a flying saucer you need to get the counter rotating
lights always at a leisurely pace - at the end of the day it's all in
consciousness. - time for bongo drums...

Post by Jim Pennino
<snip remaining puerile babble>
* Assuming of course non-relativistic speeds.

[Jim Pennino]

Post by Dave

Post by Jim Pennino

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.

Absurd perhaps to a marginally educated crackpot that doesn't understand
things like analytical geometry, slopes, and basic calculus, but the
rest of the world has found no issues* with Newton's laws of motion in
over 300 years.
If you ever perform an actual experiment, that is something real with
actual measurements, that shows Newton's laws of motion are incorrect,
you can start planning on how you will spend your Nobel Prize money.

Can't attack the argument, go for the person, like a bad soccer player.

Once more, the rest of the world has found no issues with Newton's laws
of motion in over 300 years.

Real experiments that gathered real data have been regularly performed
in physics classes across the entire planet for over 300 years and no
one has found any problems yet.

How many real experiments have you actually performed and where is the
data, crackpot?


<snip crackpot babble>

[Dave]

Post by Jim Pennino

Post by Dave

Post by Jim Pennino

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.

Absurd perhaps to a marginally educated crackpot that doesn't understand
things like analytical geometry, slopes, and basic calculus, but the
rest of the world has found no issues* with Newton's laws of motion in
over 300 years.
If you ever perform an actual experiment, that is something real with
actual measurements, that shows Newton's laws of motion are incorrect,
you can start planning on how you will spend your Nobel Prize money.

Can't attack the argument, go for the person, like a bad soccer player.

Once more, the rest of the world has found no issues with Newton's laws
of motion in over 300 years.
Real experiments that gathered real data have been regularly performed
in physics classes across the entire planet for over 300 years and no
one has found any problems yet.
How many real experiments have you actually performed and where is the
data?

Spending too much money on a pipe dream is crazy. OK on hobby budget
e.g. USD 400/month, or USD 4000/month for others.

The airtrack experiments have been showing inconsistencies for years,
but all that's said is that kinetic energy is lost in collision. What I
could do is have a 4m vacuum drop tube in my house without structural
alteration. Need to see what I can get with expected 1/1000 of a second
timer accuracy and 2mm measurement accuracy. Over 25 years ago 8 bit
micros had no problems with 1/10000 of a second reaction time due to no
operating system overhead. Basically light beam time from 0m, 1m, 2m,
3m. Then with fast spinning items, to see if there is any change, which
would be an interesting find.

[Jim Pennino]

In sci.physics Dave <***@yahoo.com> wrote:

<snip old crap>

Post by Dave
Spending too much money on a pipe dream is crazy. OK on hobby budget
e.g. USD 400/month, or USD 4000/month for others.
The airtrack experiments have been showing inconsistencies for years,

Really?

Where is your documentation for this wild claim when over 300 years of
experiments show otherwise?

Post by Dave
but all that's said is that kinetic energy is lost in collision. What I
could do is have a 4m vacuum drop tube in my house without structural
alteration. Need to see what I can get with expected 1/1000 of a second
timer accuracy and 2mm measurement accuracy. Over 25 years ago 8 bit
micros had no problems with 1/10000 of a second reaction time due to no
operating system overhead. Basically light beam time from 0m, 1m, 2m,
3m. Then with fast spinning items, to see if there is any change, which
would be an interesting find.

That a boy, go for the most expensive and complicated method that pops
out of your pea brain and ignore over 300 years of history where you
might get a clue on how to do an actual experiment.

[Dave]

Post by Jim Pennino

Post by Dave

Post by Jim Pennino

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.

Absurd perhaps to a marginally educated crackpot that doesn't understand
things like analytical geometry, slopes, and basic calculus, but the
rest of the world has found no issues* with Newton's laws of motion in
over 300 years.
If you ever perform an actual experiment, that is something real with
actual measurements, that shows Newton's laws of motion are incorrect,
you can start planning on how you will spend your Nobel Prize money.

Can't attack the argument, go for the person, like a bad soccer player.

Once more, the rest of the world has found no issues with Newton's laws
of motion in over 300 years.
Real experiments that gathered real data have been regularly performed
in physics classes across the entire planet for over 300 years and no
one has found any problems yet.
How many real experiments have you actually performed and where is the
data?

Spending too much money on a pipe dream is crazy.  OK on hobby budget
e.g. USD 400/month, or USD 4000/month for others.
The airtrack experiments have been showing inconsistencies for years,
but all that's said is that kinetic energy is lost in collision. What I
could do is have a 4m vacuum drop tube in my house without structural
alteration. Need to see what I can get with expected 1/1000 of a second
timer accuracy and 2mm measurement accuracy. Over 25 years ago 8 bit
micros had no problems with 1/10000 of a second reaction time due to no
operating system overhead. Basically light beam time from 0m, 1m, 2m,
3m. Then with fast spinning items, to see if there is any change, which
would be an interesting find.

Might be easier just to write a smartphone app, use the accelerometer,
and drop onto something soft. (say 4m drop for the timing). 0.1s
accuracy expected.

If faster than standard acceleration (9.8m/s^2) even in air, then
something is amiss.

What I do need revision on is the equations for motion where the
"acceleration" is directly proportional to the distance.

Still need formulas worked out for:
distance as a function of time
speed as a function of time.

speed as a function of distance is like: v= ks, where k is the constant
acceleration per meter of drop (about 2) and s is the distance.

[Jim Pennino]

Post by Dave

Post by Jim Pennino

Post by Dave

Post by Jim Pennino

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.

Absurd perhaps to a marginally educated crackpot that doesn't understand
things like analytical geometry, slopes, and basic calculus, but the
rest of the world has found no issues* with Newton's laws of motion in
over 300 years.
If you ever perform an actual experiment, that is something real with
actual measurements, that shows Newton's laws of motion are incorrect,
you can start planning on how you will spend your Nobel Prize money.

Can't attack the argument, go for the person, like a bad soccer player.

Once more, the rest of the world has found no issues with Newton's laws
of motion in over 300 years.
Real experiments that gathered real data have been regularly performed
in physics classes across the entire planet for over 300 years and no
one has found any problems yet.
How many real experiments have you actually performed and where is the
data?

Spending too much money on a pipe dream is crazy.  OK on hobby budget
e.g. USD 400/month, or USD 4000/month for others.
The airtrack experiments have been showing inconsistencies for years,
but all that's said is that kinetic energy is lost in collision. What I
could do is have a 4m vacuum drop tube in my house without structural
alteration. Need to see what I can get with expected 1/1000 of a second
timer accuracy and 2mm measurement accuracy. Over 25 years ago 8 bit
micros had no problems with 1/10000 of a second reaction time due to no
operating system overhead. Basically light beam time from 0m, 1m, 2m,
3m. Then with fast spinning items, to see if there is any change, which
would be an interesting find.

Might be easier just to write a smartphone app, use the accelerometer,
and drop onto something soft. (say 4m drop for the timing). 0.1s
accuracy expected.
If faster than standard acceleration (9.8m/s^2) even in air, then
something is amiss.
What I do need revision on is the equations for motion where the
"acceleration" is directly proportional to the distance.
distance as a function of time
speed as a function of time.
speed as a function of distance is like: v= ks, where k is the constant
acceleration per meter of drop (about 2) and s is the distance.

What you need is to understand 300 years of confirmed history.

[Dave]

Post by Dave

Post by Jim Pennino

Post by Dave

Post by Jim Pennino

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.

Absurd perhaps to a marginally educated crackpot that doesn't understand
things like analytical geometry, slopes, and basic calculus, but the
rest of the world has found no issues* with Newton's laws of motion in
over 300 years.
If you ever perform an actual experiment, that is something real with
actual measurements, that shows Newton's laws of motion are incorrect,
you can start planning on how you will spend your Nobel Prize money.

Can't attack the argument, go for the person, like a bad soccer player.

Once more, the rest of the world has found no issues with Newton's laws
of motion in over 300 years.
Real experiments that gathered real data have been regularly performed
in physics classes across the entire planet for over 300 years and no
one has found any problems yet.
How many real experiments have you actually performed and where is the
data?

Spending too much money on a pipe dream is crazy.  OK on hobby budget
e.g. USD 400/month, or USD 4000/month for others.
The airtrack experiments have been showing inconsistencies for years,
but all that's said is that kinetic energy is lost in collision. What
I could do is have a 4m vacuum drop tube in my house without
structural alteration. Need to see what I can get with expected 1/1000
of a second timer accuracy and 2mm measurement accuracy. Over 25 years
ago 8 bit micros had no problems with 1/10000 of a second reaction
time due to no operating system overhead. Basically light beam time
from 0m, 1m, 2m, 3m. Then with fast spinning items, to see if there is
any change, which would be an interesting find.

Might be easier just to write a smartphone app, use the accelerometer,
and drop onto something soft. (say 4m drop for the timing). 0.1s
accuracy expected.
If faster than standard acceleration (9.8m/s^2) even in air, then
something is amiss.
What I do need revision on is the equations for motion where the
"acceleration" is directly proportional to the distance.
distance as a function of time
speed as a function of time.
speed as a function of distance is like: v= ks, where k is the constant
acceleration per meter of drop (about 2) and s is the distance.

There are free accelerometer recorder smartphone apps, which work.
Already used one in my "suspicious" apps tablet, which I used for apps
which need access to shared storage etc.
Need to buy a new phone, because I'm not about to drop my regular mobile
4m, even onto soft surfaces. Need put into a nose cone with fins, after
checking if anything can be found in a drop as short as 4m. (Can be
easily laser measured to 5mm).

There are reasons why Newtonian physics may be taught, to create
clockworkers. However these reasons don't wash any more, the
educationalist science (women led) has identified the ticker tape
trolley experiment as a key point in disengagement from education, and
as a qualified and paid up Chartered Physicist I'm saying that it is
likely bad science which is being taught, which needs careful
consideration as to whether better models for kinetic energy and gravity
exist to avoid waste of human capital post BREXIT.

[Jim Pennino]

Post by Dave

Post by Dave

Post by Jim Pennino

Post by Dave

Post by Jim Pennino

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.

Absurd perhaps to a marginally educated crackpot that doesn't understand
things like analytical geometry, slopes, and basic calculus, but the
rest of the world has found no issues* with Newton's laws of motion in
over 300 years.
If you ever perform an actual experiment, that is something real with
actual measurements, that shows Newton's laws of motion are incorrect,
you can start planning on how you will spend your Nobel Prize money.

Can't attack the argument, go for the person, like a bad soccer player.

Once more, the rest of the world has found no issues with Newton's laws
of motion in over 300 years.
Real experiments that gathered real data have been regularly performed
in physics classes across the entire planet for over 300 years and no
one has found any problems yet.
How many real experiments have you actually performed and where is the
data?

Spending too much money on a pipe dream is crazy.  OK on hobby budget
e.g. USD 400/month, or USD 4000/month for others.
The airtrack experiments have been showing inconsistencies for years,
but all that's said is that kinetic energy is lost in collision. What
I could do is have a 4m vacuum drop tube in my house without
structural alteration. Need to see what I can get with expected 1/1000
of a second timer accuracy and 2mm measurement accuracy. Over 25 years
ago 8 bit micros had no problems with 1/10000 of a second reaction
time due to no operating system overhead. Basically light beam time
from 0m, 1m, 2m, 3m. Then with fast spinning items, to see if there is
any change, which would be an interesting find.

Might be easier just to write a smartphone app, use the accelerometer,
and drop onto something soft. (say 4m drop for the timing). 0.1s
accuracy expected.
If faster than standard acceleration (9.8m/s^2) even in air, then
something is amiss.
What I do need revision on is the equations for motion where the
"acceleration" is directly proportional to the distance.
distance as a function of time
speed as a function of time.
speed as a function of distance is like: v= ks, where k is the constant
acceleration per meter of drop (about 2) and s is the distance.

There are free accelerometer recorder smartphone apps, which work.
Already used one in my "suspicious" apps tablet, which I used for apps
which need access to shared storage etc.
Need to buy a new phone, because I'm not about to drop my regular mobile
4m, even onto soft surfaces. Need put into a nose cone with fins, after
checking if anything can be found in a drop as short as 4m. (Can be
easily laser measured to 5mm).
There are reasons why Newtonian physics may be taught, to create
clockworkers. However these reasons don't wash any more, the
educationalist science (women led) has identified the ticker tape
trolley experiment as a key point in disengagement from education, and
as a qualified and paid up Chartered Physicist I'm saying that it is
likely bad science which is being taught, which needs careful
consideration as to whether better models for kinetic energy and gravity
exist to avoid waste of human capital post BREXIT.

Delusional nonsense of a crackpot.

[Sylvia Else]

Post by Dave
Might be easier just to write a smartphone app, use the accelerometer,
and drop onto something soft. (say 4m drop for the timing). 0.1s
accuracy expected.
If faster than standard acceleration (9.8m/s^2) even in air, then
something is amiss.

Give it a go.

But there's no reasonable expectation that you'll find something new.
Any significant deviation from Newton's laws would have been discovered
long before now.

Post by Dave
What I do need revision on is the equations for motion where the
"acceleration" is directly proportional to the distance.

Why? There's no point in trying to find a new theory until you have
evidence that the existing theory is wrong. This is because your new
theory has to differ from the current one so that the two theories can
be distinguished by experiment. As long as the existing experiments are
consistent with the current theory, they'll either falsify your new
theory, or you'll be unable to decide which theory is correct.

Sylvia.

[Sylvia Else]

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.
Consider this setup- a falling body which can fire a rocket for a
distance of five meters to double the acceleration due to gravity of
10m/s^2 t0 20m/s^2
Also have the standard equations of F=ma (force =mass x acceleration)
and energy = force x distance
If fired at the start of a drop the five meters takes a lot longer than
if fired towards the end of a 60m drop.  This is because the falling
body is already going faster.  Yet, with energy = force x distance, the
lower down you are when the rocket is ignited, the less powder you need
because the 5m drop doesn't take as long, hence you need less and less
for the same energy (force x distance) so it becomes more and more magic.
Calculated added energy is force x distance.
Obviously the added energy is related to the burn time.
What is taught is clearly not right, since the energy added is more like
force x time. (amount of powder burnt).  Or maybe I'm completely wrong
and and misreading my data book which says
FORCE= MLT^-2  (dimensions of MASS*LENGTH/(TIME*TIME))
ENERGY = ML^2T^-2  (dimensions of MASS*LENGTH*LENGTH/(TIME*TIME))
The politics angle is that most kids give up on physics education, and I
have to say I don't blame them, because what is taught doesn't add up.
See previous posts since Dec 2022. Teaching at universities is generally
abysmal, and most students, like the lecturers don't really understand
it and learn enough to get a grade by turning the handle.

Burning the fuel is doing two things - accelerating the rocket in one
direction, and accelerating the reaction mass in the other.

If the rocket is already moving relative to an observer, then when the
rocket is fired, the rocket moves faster relative to the observer, but
the reaction mass moves slower. So from the perspective of the observer,
the rocket gets more energy, but the reaction mass gets less.

Your analysis is assuming that all the energy ends up in the rocket,
which is manifestly untrue.

Sylvia.

[Jim Pennino]

Post by Sylvia Else

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.
Consider this setup- a falling body which can fire a rocket for a
distance of five meters to double the acceleration due to gravity of
10m/s^2 t0 20m/s^2
Also have the standard equations of F=ma (force =mass x acceleration)
and energy = force x distance
If fired at the start of a drop the five meters takes a lot longer than
if fired towards the end of a 60m drop.  This is because the falling
body is already going faster.  Yet, with energy = force x distance, the
lower down you are when the rocket is ignited, the less powder you need
because the 5m drop doesn't take as long, hence you need less and less
for the same energy (force x distance) so it becomes more and more magic.
Calculated added energy is force x distance.
Obviously the added energy is related to the burn time.
What is taught is clearly not right, since the energy added is more like
force x time. (amount of powder burnt).  Or maybe I'm completely wrong
and and misreading my data book which says
FORCE= MLT^-2  (dimensions of MASS*LENGTH/(TIME*TIME))
ENERGY = ML^2T^-2  (dimensions of MASS*LENGTH*LENGTH/(TIME*TIME))
The politics angle is that most kids give up on physics education, and I
have to say I don't blame them, because what is taught doesn't add up.
See previous posts since Dec 2022. Teaching at universities is generally
abysmal, and most students, like the lecturers don't really understand
it and learn enough to get a grade by turning the handle.

Burning the fuel is doing two things - accelerating the rocket in one
direction, and accelerating the reaction mass in the other.
If the rocket is already moving relative to an observer, then when the
rocket is fired, the rocket moves faster relative to the observer, but
the reaction mass moves slower. So from the perspective of the observer,
the rocket gets more energy, but the reaction mass gets less.
Your analysis is assuming that all the energy ends up in the rocket,
which is manifestly untrue.
Sylvia.

There is also the little issue that a rocket does not obey the
Newton equations for linear motion for the blazingly obvious reason
that the mass is constantly changing.

[Dave]

Post by Sylvia Else

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.
Consider this setup- a falling body which can fire a rocket for a
distance of five meters to double the acceleration due to gravity of
10m/s^2 t0 20m/s^2
Also have the standard equations of F=ma (force =mass x acceleration)
and energy = force x distance
If fired at the start of a drop the five meters takes a lot longer
than if fired towards the end of a 60m drop.  This is because the
falling body is already going faster.  Yet, with energy = force x
distance, the lower down you are when the rocket is ignited, the less
powder you need because the 5m drop doesn't take as long, hence you
need less and less for the same energy (force x distance) so it
becomes more and more magic.
Calculated added energy is force x distance.
Obviously the added energy is related to the burn time.
What is taught is clearly not right, since the energy added is more
like force x time. (amount of powder burnt).  Or maybe I'm completely
wrong and and misreading my data book which says
FORCE= MLT^-2  (dimensions of MASS*LENGTH/(TIME*TIME))
ENERGY = ML^2T^-2  (dimensions of MASS*LENGTH*LENGTH/(TIME*TIME))
The politics angle is that most kids give up on physics education, and
I have to say I don't blame them, because what is taught doesn't add
up. See previous posts since Dec 2022. Teaching at universities is
generally abysmal, and most students, like the lecturers don't really
understand it and learn enough to get a grade by turning the handle.

Burning the fuel is doing two things - accelerating the rocket in one
direction, and accelerating the reaction mass in the other.
If the rocket is already moving relative to an observer, then when the
rocket is fired, the rocket moves faster relative to the observer, but
the reaction mass moves slower. So from the perspective of the observer,
the rocket gets more energy, but the reaction mass gets less.
Your analysis is assuming that all the energy ends up in the rocket,
which is manifestly untrue.

If you buy a 200N rocket you expect to get 200N of thrust. There is only
one rocket mass, and for the short time say 400g of fuel used on a 20kg
mass isn't that much.

Post by Sylvia Else
Sylvia.

[Dave]

Post by Sylvia Else

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.
Consider this setup- a falling body which can fire a rocket for a
distance of five meters to double the acceleration due to gravity of
10m/s^2 t0 20m/s^2
Also have the standard equations of F=ma (force =mass x acceleration)
and energy = force x distance
If fired at the start of a drop the five meters takes a lot longer
than if fired towards the end of a 60m drop.  This is because the
falling body is already going faster.  Yet, with energy = force x
distance, the lower down you are when the rocket is ignited, the less
powder you need because the 5m drop doesn't take as long, hence you
need less and less for the same energy (force x distance) so it
becomes more and more magic.
Calculated added energy is force x distance.
Obviously the added energy is related to the burn time.
What is taught is clearly not right, since the energy added is more
like force x time. (amount of powder burnt).  Or maybe I'm completely
wrong and and misreading my data book which says
FORCE= MLT^-2  (dimensions of MASS*LENGTH/(TIME*TIME))
ENERGY = ML^2T^-2  (dimensions of MASS*LENGTH*LENGTH/(TIME*TIME))
The politics angle is that most kids give up on physics education, and
I have to say I don't blame them, because what is taught doesn't add
up. See previous posts since Dec 2022. Teaching at universities is
generally abysmal, and most students, like the lecturers don't really
understand it and learn enough to get a grade by turning the handle.

Burning the fuel is doing two things - accelerating the rocket in one
direction, and accelerating the reaction mass in the other.
If the rocket is already moving relative to an observer, then when the
rocket is fired, the rocket moves faster relative to the observer, but
the reaction mass moves slower. So from the perspective of the observer,
the rocket gets more energy, but the reaction mass gets less.
Your analysis is assuming that all the energy ends up in the rocket,
which is manifestly untrue.

If you buy a 200N rocket you expect to get 200N of thrust. There is only
one rocket mass, and for the short time say 400g of fuel used on a 20kg
mass isn't that much.

Post by Sylvia Else
Sylvia.

[Dave]

Post by Sylvia Else

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.
Consider this setup- a falling body which can fire a rocket for a
distance of five meters to double the acceleration due to gravity of
10m/s^2 t0 20m/s^2
Also have the standard equations of F=ma (force =mass x acceleration)
and energy = force x distance
If fired at the start of a drop the five meters takes a lot longer
than if fired towards the end of a 60m drop.  This is because the
falling body is already going faster.  Yet, with energy = force x
distance, the lower down you are when the rocket is ignited, the less
powder you need because the 5m drop doesn't take as long, hence you
need less and less for the same energy (force x distance) so it
becomes more and more magic.
Calculated added energy is force x distance.
Obviously the added energy is related to the burn time.
What is taught is clearly not right, since the energy added is more
like force x time. (amount of powder burnt).  Or maybe I'm completely
wrong and and misreading my data book which says
FORCE= MLT^-2  (dimensions of MASS*LENGTH/(TIME*TIME))
ENERGY = ML^2T^-2  (dimensions of MASS*LENGTH*LENGTH/(TIME*TIME))
The politics angle is that most kids give up on physics education, and
I have to say I don't blame them, because what is taught doesn't add
up. See previous posts since Dec 2022. Teaching at universities is
generally abysmal, and most students, like the lecturers don't really
understand it and learn enough to get a grade by turning the handle.

Burning the fuel is doing two things - accelerating the rocket in one
direction, and accelerating the reaction mass in the other.
If the rocket is already moving relative to an observer, then when the
rocket is fired, the rocket moves faster relative to the observer, but
the reaction mass moves slower. So from the perspective of the observer,
the rocket gets more energy, but the reaction mass gets less.
Your analysis is assuming that all the energy ends up in the rocket,
which is manifestly untrue.

If you buy a 200N rocket you expect to get 200N of thrust. There is only
one rocket mass, and for the short time say 400g of fuel used on a 20kg
mass isn't that much.

Post by Sylvia Else
Sylvia.

[Sylvia Else]

Post by Dave

Post by Sylvia Else

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.
Consider this setup- a falling body which can fire a rocket for a
distance of five meters to double the acceleration due to gravity of
10m/s^2 t0 20m/s^2
Also have the standard equations of F=ma (force =mass x acceleration)
and energy = force x distance
If fired at the start of a drop the five meters takes a lot longer
than if fired towards the end of a 60m drop.  This is because the
falling body is already going faster.  Yet, with energy = force x
distance, the lower down you are when the rocket is ignited, the less
powder you need because the 5m drop doesn't take as long, hence you
need less and less for the same energy (force x distance) so it
becomes more and more magic.
Calculated added energy is force x distance.
Obviously the added energy is related to the burn time.
What is taught is clearly not right, since the energy added is more
like force x time. (amount of powder burnt).  Or maybe I'm completely
wrong and and misreading my data book which says
FORCE= MLT^-2  (dimensions of MASS*LENGTH/(TIME*TIME))
ENERGY = ML^2T^-2  (dimensions of MASS*LENGTH*LENGTH/(TIME*TIME))
The politics angle is that most kids give up on physics education,
and I have to say I don't blame them, because what is taught doesn't
add up. See previous posts since Dec 2022. Teaching at universities
is generally abysmal, and most students, like the lecturers don't
really understand it and learn enough to get a grade by turning the
handle.

Burning the fuel is doing two things - accelerating the rocket in one
direction, and accelerating the reaction mass in the other.
If the rocket is already moving relative to an observer, then when the
rocket is fired, the rocket moves faster relative to the observer, but
the reaction mass moves slower. So from the perspective of the
observer, the rocket gets more energy, but the reaction mass gets less.
Your analysis is assuming that all the energy ends up in the rocket,
which is manifestly untrue.

If you buy a 200N rocket you expect to get 200N of thrust. There is only
one rocket mass, and for the short time say 400g of fuel used on a 20kg
mass isn't that much.

Post by Sylvia Else
Sylvia.

How is that in any way connected with what I said?

Sylvia.

[Jim Pennino]

Post by Dave

Post by Sylvia Else

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.
Consider this setup- a falling body which can fire a rocket for a
distance of five meters to double the acceleration due to gravity of
10m/s^2 t0 20m/s^2
Also have the standard equations of F=ma (force =mass x acceleration)
and energy = force x distance
If fired at the start of a drop the five meters takes a lot longer
than if fired towards the end of a 60m drop.  This is because the
falling body is already going faster.  Yet, with energy = force x
distance, the lower down you are when the rocket is ignited, the less
powder you need because the 5m drop doesn't take as long, hence you
need less and less for the same energy (force x distance) so it
becomes more and more magic.
Calculated added energy is force x distance.
Obviously the added energy is related to the burn time.
What is taught is clearly not right, since the energy added is more
like force x time. (amount of powder burnt).  Or maybe I'm completely
wrong and and misreading my data book which says
FORCE= MLT^-2  (dimensions of MASS*LENGTH/(TIME*TIME))
ENERGY = ML^2T^-2  (dimensions of MASS*LENGTH*LENGTH/(TIME*TIME))
The politics angle is that most kids give up on physics education, and
I have to say I don't blame them, because what is taught doesn't add
up. See previous posts since Dec 2022. Teaching at universities is
generally abysmal, and most students, like the lecturers don't really
understand it and learn enough to get a grade by turning the handle.

Burning the fuel is doing two things - accelerating the rocket in one
direction, and accelerating the reaction mass in the other.
If the rocket is already moving relative to an observer, then when the
rocket is fired, the rocket moves faster relative to the observer, but
the reaction mass moves slower. So from the perspective of the observer,
the rocket gets more energy, but the reaction mass gets less.
Your analysis is assuming that all the energy ends up in the rocket,
which is manifestly untrue.

If you buy a 200N rocket you expect to get 200N of thrust. There is only
one rocket mass, and for the short time say 400g of fuel used on a 20kg
mass isn't that much.

For a rocket, the governing equation is:

delta v = Ve * ln (M0/Mf)

Where:

delta v is the change in velocity
Ve is the effective exhaust velocity
ln is the natural logarithm function
M0 is the intial total mass
Mf is the final total mass

Ve = Isp * G

Where:

Isp is the specific impulse in dimension of time
G is standard gravity.

[Dave]

Post by Jim Pennino

Post by Dave

Post by Sylvia Else

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.
Consider this setup- a falling body which can fire a rocket for a
distance of five meters to double the acceleration due to gravity of
10m/s^2 t0 20m/s^2
Also have the standard equations of F=ma (force =mass x acceleration)
and energy = force x distance
If fired at the start of a drop the five meters takes a lot longer
than if fired towards the end of a 60m drop.  This is because the
falling body is already going faster.  Yet, with energy = force x
distance, the lower down you are when the rocket is ignited, the less
powder you need because the 5m drop doesn't take as long, hence you
need less and less for the same energy (force x distance) so it
becomes more and more magic.
Calculated added energy is force x distance.
Obviously the added energy is related to the burn time.
What is taught is clearly not right, since the energy added is more
like force x time. (amount of powder burnt).  Or maybe I'm completely
wrong and and misreading my data book which says
FORCE= MLT^-2  (dimensions of MASS*LENGTH/(TIME*TIME))
ENERGY = ML^2T^-2  (dimensions of MASS*LENGTH*LENGTH/(TIME*TIME))
The politics angle is that most kids give up on physics education, and
I have to say I don't blame them, because what is taught doesn't add
up. See previous posts since Dec 2022. Teaching at universities is
generally abysmal, and most students, like the lecturers don't really
understand it and learn enough to get a grade by turning the handle.

Burning the fuel is doing two things - accelerating the rocket in one
direction, and accelerating the reaction mass in the other.
If the rocket is already moving relative to an observer, then when the
rocket is fired, the rocket moves faster relative to the observer, but
the reaction mass moves slower. So from the perspective of the observer,
the rocket gets more energy, but the reaction mass gets less.
Your analysis is assuming that all the energy ends up in the rocket,
which is manifestly untrue.

If you buy a 200N rocket you expect to get 200N of thrust. There is only
one rocket mass, and for the short time say 400g of fuel used on a 20kg
mass isn't that much.

delta v = Ve * ln (M0/Mf)
delta v is the change in velocity
Ve is the effective exhaust velocity
ln is the natural logarithm function
M0 is the intial total mass
Mf is the final total mass
Ve = Isp * G
Isp is the specific impulse in dimension of time
G is standard gravity.

What may be an interesting find is if, when firing down, the
gravitational acceleration and the rocket acceleration doesn't add up in
a linear way. Newton says it should, since gravity is a force in one
direction, relativity says it shouldn't (maybe) since you are forcing
against the natural inclination of the space. The only way this may work
with any understanding I have is to increase the inertial mass, even at
a low speed.

[Sylvia Else]

since you are forcing against the natural inclination of the space

You can you fail to realise that this is gibberish.

Sylvia.

[Sylvia Else]

since you are forcing against the natural inclination of the space

How can you fail to realise that this is gibberish?

Sylvia.

[Incubus]

Post by Dave
Absurdity of taught mechanics when firing rockets down - evidence of
magic powder.
Consider this setup- a falling body which can fire a rocket for a
distance of five meters to double the acceleration due to gravity of
10m/s^2 t0 20m/s^2
Also have the standard equations of F=ma (force =mass x acceleration)
and energy = force x distance
If fired at the start of a drop the five meters takes a lot longer than
if fired towards the end of a 60m drop. This is because the falling
body is already going faster. Yet, with energy = force x distance, the
lower down you are when the rocket is ignited, the less powder you need
because the 5m drop doesn't take as long, hence you need less and less
for the same energy (force x distance) so it becomes more and more magic.
Calculated added energy is force x distance.
Obviously the added energy is related to the burn time.
What is taught is clearly not right, since the energy added is more like
force x time. (amount of powder burnt). Or maybe I'm completely wrong
and and misreading my data book which says
FORCE= MLT^-2 (dimensions of MASS*LENGTH/(TIME*TIME))
ENERGY = ML^2T^-2 (dimensions of MASS*LENGTH*LENGTH/(TIME*TIME))

You keep claiming that what is taught isn't right. Have you considered
that your level of understanding is the issue?