00:01
Hello.
00:04
So uh we have to do some estimates for uh first velocity.
00:12
So if you're looking at the velocity of the ball, a reasonable estimate would be uh you know 4.2 may just be a second.
00:24
Okay so this velocity here is an estimate.
00:30
So the first quality is gonna be velocity 4.2.
00:34
Okay so the next quantity is gonna be the uh coefficient of friction.
00:43
Uh so you'll see that this is very small.
00:48
Obviously they want to reduce uh friction as much as possible on the floor.
00:54
Okay? so that the ball uh can roll.
00:58
Okay so the second estimate for the coefficient of candidate friction because there's motion, it's gonna be a .1-0.
01:07
Okay estimated.
01:10
I'll give you, okay so now i have the linear velocity we have.
01:16
You know that friction is um u.
01:18
N.
01:18
N.
01:18
Is the number of force? okay.
01:20
And the normal force is uh mg.
01:24
Okay, so if you have a body lying on the floor, the number of forces up.
01:30
The weight is down loops.
01:36
The weight is down.
01:37
Okay, so they are balanced by each other to and it's got two mg.
01:42
Okay, so f fraction will be me.
01:45
Okay, times n n is mg.
01:47
Okay, now the friction is going to provide a talk because if there's no friction, the ball is just gonna slide, it's not going to rotate.
02:00
Okay, so the talk is given by the frictional force that the radius of the ball.
02:07
Okay, so we have that we did a refreshing is mu mg.
02:14
Right, so this is what is that uh for uh the ball the movement of in asia i is to m.
02:24
R squared of five.
02:25
You know, the ball is in the form of a sphere.
02:27
Okay, so that's two a.m. r squared over five.
02:32
Of course this talk right here is also a boat to no asia times angular acceleration.
02:39
Okay, so you see that here...