00:01
Here we have to solve the following problem.
00:03
The car is traveling with the initial velocity of 24 .8 meters per second and the driver spots an alligator when the separation between driver and alligator is 80 .8 meters.
00:20
However, the driver needs delta t of 0 .21 second to start to react.
00:29
And then he starts to apply acceleration and then stops.
00:35
So we have to find the magnitude of this acceleration.
00:39
So let's illustrate this system.
00:41
So let's introduce x coordinate and here we will place an alligator.
00:49
Initially the driver is here at the distance of l from the alligator.
01:01
After some distance, which is v0.
01:04
V0 times delta t, the driver starts to decelerate, and we have to calculate this acceleration, which occurs at this stage of travel.
01:18
So it means that first the driver travels for some distance l0, which is v0 times delta t, and that equals to 24 .8 meters per second times 0 .21 second.
01:51
That equals to 5 .208 seconds, 2 .8 meters, which is 5 .21 meter...