00:02
In this problem, rain hits the windshield, the side windshield with a side window of a moving car and makes a streak going along the window at a 45 degree angle.
00:15
Then we want to determine the speed of the car relative to the speed of the raindrop.
00:21
And we assume the raindrop is moving vertically at a constant speed.
00:24
So straight down at a constant speed.
00:27
So we're going to evaluate the movement of the raindrop.
00:30
It starts from position a, let's say, and ends up position b.
00:35
And we know that this is a 45 degree angle.
00:44
And more than just that it moves this way, we know that its velocity is in this direction.
00:49
And that's more important.
00:50
So as we're addressing velocity in this question, so its velocity is, can be determined just by the direction that it moves.
01:01
So if it has this 45 degree movement, that means the angle of the velocity is also this 45.
01:09
And we're going to break up the velocity into its components in the direction of the initial velocity of the raindrop, the vertical velocity...