# Impulse and Force

1. Jan 22, 2004

### kishtik

Is it enough to know the momentums of the balls (and the angle) to determine what force they exert on each other when they collide?

I know F delta t = m delta v but how can I know the time?

2. Jan 22, 2004

You can't!

Your question seems very lacking in detail...

3. Jan 22, 2004

### kishtik

I mean isn't there a way that I can know the force they exert on each other without knowing the time they thouch each other?

Thanks.

4. Jan 22, 2004

### FZ+

In a word, no.

5. Jan 23, 2004

### kishtik

But there must be a way to calculate their velocities after the collision.

6. Jan 23, 2004

### HallsofIvy

Yes, of course there is. That WASN'T your question before.
You may be thinking that since you know change in speed you must be able to find the force.

That's not correct. If you knew acceleration you would able to find the force but knowing what acceleration causes the change in force would require that you know the time in which the change takes place.

7. Jan 23, 2004

Ok thanks.