00:01
At this instance, we have this situation.
00:02
At this instance, a chose a ball, chose a football with an initial speed of 20 meters per second, 60 degrees from the horizontal.
00:13
So, 4c undergoes projectile motion.
00:20
And then when, at the instance when the ball is thrown, b starts to run forward.
00:27
We need to find the speed of b in order for b to catch the ball.
00:31
Successfully and we also need to find the velocity of c relative to be at the incident of catch as well as the acceleration of c r2 to be at the instance of catch.
00:41
Okay so to do this first we need to so we recognize that the football is doing projectile motion so we can find the time of light okay that's the time of light of c bt, okay, so we have we using v -0 -vy is equal to v -y -0 plus a -y -t, okay, and ticking downward to be positive.
01:31
So we look at the ball, so this is the projectile, okay, this is the initial, and then this is the final, okay, all right, so this is this is the final, then the data are the same.
02:04
In this case, 60 degrees.
02:07
So the final y components, the y components of the final velocity will be re -signed data, and then the initial, the y components of the initial velocity is negative resigned data, and then class gt.
02:25
So we can find t to be 2v sine data...