00:01
Okay, so we have a kicker that is kicking a ball at an angle of 51 degrees, so that's theta, and it's got some initial velocity of 24 meters per second.
00:17
And we want to know where this ball is going to be vertically, and if it's going to make it over this bar here.
00:28
So the bar is 3 .05 meters up.
00:35
And it is a distance of 36 meters from where it is kicked.
00:46
So we want to know where it's going to be when it crosses up here, or if it's going to make it over at all.
00:54
Okay.
00:55
So the first thing we can do using the horizontal component, is figure out the time that it's going to get there and then use that in an equation for the vertical component.
01:12
So our x component, horizontal component of the velocity is going to be the magnitude of the velocity initially times the cosine of the angle theta.
01:25
And for v y, that's going to be the initial times sine.
01:31
Of theta.
01:33
Okay, so this is vx initial and vy initial.
01:40
Okay, so to find the time, we can just, because there's no acceleration in the x direction, we can just say t is going to be equal to the distance, delta x, so the distance it travels horizontally over its initial velocity in the x direction.
02:02
So that's going to be 30, meters over 24 meters per second times cosine of 51 degrees and that's going to give us 2 .38 seconds.
02:25
So that means we know that it's going to be, so the ball at 2 .38 seconds is going to be somewhere over here...