Assistance on Physics experiment. Please help

[youngvuth]

I am supposed to find out how mass affects the time it takes a ping pong ball to fall a certain distance. Can somebody help with information please? My belief is that the more water the faster it'll fall.

[Roger Dynamic Motion]

My belief is that the more water the faster it'll fall. ___ / What does that mean ?

[StringJunky]

I am supposed to find out how mass affects the time it takes a ping pong ball to fall a certain distance. Can somebody help with information please? My belief is that the more water the faster it'll fall.

If you drop a feather and a cannon ball, at the same time in a volume with no air in it, they will touch the bottom at the same time. What does that tell you about the effect of mass on the rate an object falls?

[Roger Dynamic Motion]

The mass will created a force at the contact time with the surface much greater than the feather

Edited April 30, 2017 by Roger Dynamic Motion

[StringJunky]

The mass will created a force at the contact time with the surface much greater than the feather

But that doesn't mean it's falling faster

 

This is done in a very large vacuum chamber:

Edited April 30, 2017 by StringJunky

[Roger Dynamic Motion]

This is done in a very large vacuum chamber:

 

No ~ the time of the fall is relative...

Edited April 30, 2017 by Roger Dynamic Motion

[Strange]

This is done in a very large vacuum chamber:

 

No ~ the time of the fall is relative...

 

 

Relative to what?

I am supposed to find out how mass affects the time it takes a ping pong ball to fall a certain distance. Can somebody help with information please? My belief is that the more water the faster it'll fall.

 

Are you considering air resistance? In which case, the mass will make a difference because the terminal velocity will be higher:

https://en.wikipedia.org/wiki/Terminal_velocity

[pzkpfw]

(

...and on the Moon:

)

[StringJunky]

(

...and on the Moon:

)

Forgot about that one.

[Strange]

(

...and on the Moon:

)

 

 

That might be beyond the budget of a school science experiment, though...

[MigL]

Not sure I quite understand the experiment, but he may be adding mass to the ping-pong ball by filling it with water.

If he then drops it and measures the time to fall, he will have a variable mass but constant air resistance.

[StringJunky]

Not sure I quite understand the experiment, but he may be adding mass to the ping-pong ball by filling it with water.

If he then drops it and measures the time to fall, he will have a variable mass but constant air resistance.

He'll record the same times, won't he?

[pzkpfw]

He'll record the same times, won't he?

Not when dropped in air. Air causes drag. Drag is a force. The different masses of the pin pong ball and ping pong ball full of water then makes a difference.

 

 

(

Extreme example: a parachutist vs a parachutist whose chute didn't open - same mass, different rate of fall.

 

Of course, the two ping pong balls have the same shape, but ...

)

 

 

https://www.quora.com/If-we-drop-different-weights-from-same-height-which-will-fall-first-to-ground

Edited May 1, 2017 by pzkpfw

[Roger Dynamic Motion]

The question was !~

 

If you drop a feather and a cannon ball, at the same time in a volume with no air in it, they will touch the bottom at the same time. What does that tell you about the effect of mass on the rate an object falls?

No ~ the time of the fall is relative... to any object falling in vacuum.

Edited May 1, 2017 by Roger Dynamic Motion

[StringJunky]

Not when dropped in air. Air causes drag. Drag is a force. The different masses of the pin pong ball and ping pong ball full of water then makes a difference.

 

 

(

Extreme example: a parachutist vs a parachutist whose chute didn't open - same mass, different rate of fall.

 

Of course, the two ping pong balls have the same shape, but ...

)

 

 

https://www.quora.com/If-we-drop-different-weights-from-same-height-which-will-fall-first-to-ground

I thought if all parameters stay the same, except the mass, it would be the same effect as if they were in a vacuum; the degree of drag would be the same because they are the same size and shape and force of gravity would be the same. The only difference in results between the experiment done in a vacuum and air is the actual time it takes for the objects to fall in either setup.

Edited May 1, 2017 by StringJunky

[pzkpfw]

I thought if all parameters stay the same, except the mass, it would be the same effect as if they were in a vacuum; the degree of drag would be the same because they are the same size and shape and force of gravity would be the same. The only difference in results between the experiment done in a vacuum and air is the actual time it takes for the objects to fall in either setup.

Mass is one of the factors in terminal velocity. So the weighted ball will get faster than the unweighted ball.

 

(Been trying to find a good worked example. For a start: https://en.wikipedia.org/wiki/Terminal_velocity#Derivation_for_terminal_velocity )

[StringJunky]

Mass is one of the factors in terminal velocity. So the weighted ball will get faster than the unweighted ball.

 

(Been trying to find a good worked example. For a start: https://en.wikipedia.org/wiki/Terminal_velocity#Derivation_for_terminal_velocity )

So, what you are saying is that there is reaction between the mass and air that is not present in a vacuum?

[MigL]

In a vacuum there is no terminal velocity.

The acceleration of any test mass is solely dependent on the mass of the Earth ( little m cancels out from ma=GmM/r^2) and radius.

While in air, when the gravitational force is equal to the drag force, there is no more acceleration. And since drag is NOT dependent on mass, m cannot cancel out.

I.E. we have a mass ( m ) dependence to acceleration and terminal velocity.

Edited May 1, 2017 by MigL

[StringJunky]

In a vacuum there is no terminal velocity.

The acceleration of any test mass is solely dependent on the mass of the Earth ( little m cancels out from ma=GmM/r^2) and radius.

While in air, when the gravitational force is equal to the drag force, there is no more acceleration. And since drag is NOT dependent on mass, m cannot cancel out.

I.E. we have a mass ( m ) dependence to acceleration and terminal velocity.

OK. Thanks.

[Strange]

The question was !~

 

If you drop a feather and a cannon ball, at the same time in a volume with no air in it, they will touch the bottom at the same time. What does that tell you about the effect of mass on the rate an object falls?

No ~ the time of the fall is relative... to any object falling in vacuum.

 

 

I have no idea what that is supposed to mean. But it sounds wrong.

 

In a vacuum the feather and the canonball will fall at the same rate and hit the floor at the same time. The time is not relative to the mass (or shape) of the objects.

[Roger Dynamic Motion]

The time of the fall is relative..''with any environment'', to any object falling trough vacuum or trough the air

Edited May 1, 2017 by Roger Dynamic Motion

[Strange]

The time of the fall is relative..''with any environment'', to any object falling trough vacuum or trough the air

What does that even mean?

[Roger Dynamic Motion]

the one is the same to the other.. only different with the result @!~

Edited May 2, 2017 by Roger Dynamic Motion

[Manticore]

the one is the same to the other.. only different with the result @!~

Guaranteed content free.

[Strange]

the one is the same to the other.. only different with the result @!~

This makes no sense.