00:01
Here we have some facts about the deceleration of a car.
00:05
First, we're told that its acceleration rate, which is actually a deceleration since it's slowing down, is negative 15 feet per second square.
00:15
Its velocity at the time of zero is 60 feet per second, and its position function at the time of zero is zero.
00:28
If we wanted to figure the velocity function, we would integrate the acceleration, and that would be negative 15t plus a constant.
00:43
That constant we could actually find because we do know the velocity at zero is 60.
00:49
So if i filled in zero for time, i should get a velocity of 60.
00:55
So let's do that.
00:57
Velocity is 60 when t is zero.
00:58
And if i fill in zero for t, i'd have 60 equals 0 plus c, which really is just another way of saying c is 60.
01:07
So let's remove that 60, that's c, and let's put plus 60.
01:15
The position function is the integral of the velocity.
01:21
So that would be negative 15 t squared over 2 plus 60t plus a constant.
01:34
Well, once again, we know the position at zero...