00:01
Okay, the gravitational force on a baseball is minus f sub g.
00:13
The pitcher throws the baseball with a velocity v -i -hat by uniformly accelerating it straightforward horizontally.
00:22
So he inserts some force this way.
00:28
Actually, this force will be probably something like that.
00:34
Um, for a time t, if the ball starts at rest, determine the following, uh, through what distance does it accelerate before its release and what force does the pitcher exert on the ball.
00:47
So the pitcher has the ball and it moves through some distance before it's released, right? he accelerates it for some distance.
01:05
We'll call that distance d.
01:11
So what is that distance? we can use a kinematic equation, which tells us that x final, and let's say this is x equals 0, so x final is equal to x initial plus the initial velocity times time, plus one half the acceleration times times squared.
01:33
The initial x is 0, the initial velocity in the x is 0.
01:38
So that distance d, that it's accelerated through, is equal to one half times the acceleration times the time squared.
01:51
Okay, part b, what force does the pitcher exert on the ball? well, to do this, we need to look at the forces...