Elastic Collisions/Impulse


I'm in over my head right now. I don't even know how to start this problem.

A 12 gram bouncy ball is dropped from height (h) and lands on a force meter and bounces back up. The magnitude of Force is 85N and the time this whole process takes is 8 milliseconds.

There is a graph of a triangle representing the problem. The triangle is 8.5 divisions (units) high and the base of the triangle is 8 units long.

The x-axis is time and that's where we get the 8ms from, the base of the triangle is 8 divisions long.
The y-axis is force, each division being 10N. The height of the triangle is 8.5 divisions.

I was thinking that when considering time I would only be concerned with the 4ms mark, as that would be the peak of the event (the ball hits the force meter).

Any help would be awesome, I can't even get the ball (no pun intended) rolling.

so what's the question?

I havent dealt with physics in a long time so i am no service to you haha ....however i would like to know the answer too simply because i'm a geek.

cramster.com is the best site you will ever find.

Over 9000.

phunny said:

cramster.com is the best site you will ever find.

Click to expand...

Looks like a pretty cool site. It's like DSMtuners for homework! I'll check it out for next time.

If I even had a formula to start with life would be so much easier.
All I can find are formulas for 2 dimensional elastic collisions. Since the force plate isn;t going anywhere, I don't think they apply.

I still don't see what you're trying to solve for. You have the time, and you have the force, and you're calculating it on a graph. What is the question?

I was good in physics but as the few have said. What is being ask for?

It seem like you have all the variables but what are you trying to solve for? Are you looking for the height in which the ball was initially drop?

You have all the required variables, but what are you trying to solve exactly, please excuse me if I'm out of place, but I do not see the actual question.

How did it only take 8 milliseconds for the ball to drop and bounce back up?

4 million KPH ball speed, and zero mass?

What planet is this occurring on (to account for gravity and air density) and what is the coeffecient of drag of the ball's surface? Of course, if the ball returns to the same point from which it was dropped, we can assume that it's a frictionless universe, and that no energy was lost/transferred from the action of bouncing. This would be an interesting universe to live in.