00:01
Alright, so we're going to have a problem about a golf ball being hit by a golfer or a golf club.
00:07
And we're asked to do some things about it.
00:10
So this is going to be involving a collision and some momentum and some impulse.
00:14
So pull those tools out.
00:17
They're given that the golf ball is a mass of 46 grams.
00:21
We'll convert that to kilograms later.
00:23
And that a good golfer can get an exit velocity of that ball of 61 meters per second.
00:28
So part a is find a slow motion.
00:30
Video of a golf ball being hit on youtube and watch it.
00:33
So go do that.
00:35
Part b is what is the momentum of the ball just after impact? well, after impact, it's going at 61 meters per second.
00:44
It's got a mass of 46 grams.
00:47
So momentum is mass times velocity.
00:50
So we can calculate the momentum in that ball.
00:52
We're going to convert my mass of my ball into kilograms, kilograms times 61 meters per second and i can do that in the calculator and get 2 .806 kilogram meters per second as the momentum of my ball.
01:15
Part c is the collision between the club and the ball lasts for a time of 0 .5 milliseconds, which they give you as 0 .4, 3 zeros, excuse me, 5 seconds.
01:36
What is the average force? so what is the force average on this? well, we know that the force, the average force, right, is the change in momentum divided by the change in time.
01:50
So the change in momentum, it starts at zero, the golf ball, right? so the change of momentum is just that final momentum, 2 .806, divided by the change in time, which is what is given here.
02:02
And so our average force, popping that into a calculator, is 5 ,612 newtons.
02:24
Part d, they ask the club head of a driver is a mass of 200 grams, so the mass of the club is 200 grams, which is 0 .2 kilograms.
02:38
It might be helpful later...