How does force change momentum?

[Kamal]

Let's say we are in outer space.Suppose I have 2 metallic balls A and B with initial velocity 0 and same mass M and a baseball bat.Let's say I hit the ball A with force F and ball B with F' in such a way that F>F'.Ball A attain final velocity V in time T and ball B attain final velocity V' in time T'.Let's say D is distance traveled by A in time T and D' is distance traveled by B in time T'.I know that V >V'.Please say whether T>T' or vice versa and D>D' or vice versa.

 

[phinds]

Let's say we are in outer space.Suppose I have 2 metallic balls A and B with initial velocity 0 and same mass M and a baseball bat.Let's say I hit the ball A with force F and ball B with F' in such a way that F>F'.Ball A attain final velocity V in time T and ball B attain final velocity V' in time T'.Let's say D is distance traveled by A in time T and D' is distance traveled by B in time T'.I know that V >V'.Please say whether T>T' or vice versa and D>D' or vice versa.

What do YOU think, and why?

@Kamal I see that you are new to the forum so you may be under the mistaken impression that this is a Q&A forum where you just ask a question and get the answer. It is not. We expect you to give your own answers and explain your own thought process and then we can help if you have gone wrong.

 

[russ_watters]

Thread moved to classical physics.

 

[Dale]

Let's say I hit the ball A with force F and ball B with F' in such a way that F>F'.Ball A attain final velocity V in time T and ball B attain final velocity V' in time T'. ... I know that V >V'.

Actually, we do not know that V>V' because we are not given any information about T or T'.

 

[Kamalesh]

Actually, we do not know that V>V' because we are not given any information about T or T'.

Since F>F' and initial velocity is zero we can say V>V' because greater the force greater will be the energy transferred greater the energy transferred greater will be the final velocity.

 

[Dale]

Since F>F' and initial velocity is zero we can say V>V' because greater the force greater will be the energy transferred greater the energy transferred greater will be the final velocity.

This is not correct. What will happen if F = 10 N and F' = 5 N (F>F') and if T = 1 s and T' = 10 s?

 

[Delta2]

The "logical path" that I consider to take on this, is first to make the logical assumption that the times T,T' will be both small and approximately equal (since we hit the balls with a baseball bat). And since F>F' the momentum transfer to the balls is FT and F'T'=F'T with FT>F'T, and since balls have equal mass, it follows that V>V'.

 

[Dale]

first to make the logical assumption that the times T,T' will be both small and approximately equal (since we hit the balls with a baseball bat)

I agree that is a logical and a good assumption generally, but unfortunately the problem is that in the end the OP wants to know:

whether T>T' or vice versa and D>D' or vice versa.

So by making that assumption you are directly assuming part of the desired conclusion. That may not be a problem for the OP, but I think they need to be explicit.

If I were to recommend additional assumptions I would make the assumption that the two balls could be modeled as springs with identical modulus of elasticity and the bat could be modeled as rigid.

 

[gmax137]

I'm not sure exactly what the OP is after. "Hit the ball A with force F" is kind of ambiguous; it is certainly different than "push with force F for T seconds" or "push with force F for D meters."

Hitting with a bat implies an interest in Impulse not Force.

Until this is clarified the discussion has little meaning.

 

[phinds]

Until this is clarified the discussion has little meaning.

Yeah, that is SUCH a problem on this forum. People just pile on even after an OP has been asked to clarify something or explain HIS though processes but has made zero response, as in this case. I've been noticing that more and more lately but it has always been the case at least to some extent.