Question

A car is traveling at a constant speed of 24 meters per second when all of a sudden the driver notices a deer 60 meters in front of him. Given that he has a reaction time of 1.2 seconds and that he can slow down at a rate of 6 m/s2, does he hit the deer? If so, at what speed does he hit the deer?

Answer 1

`{v2 }^(2) - {v1}^(2) = 2a(x2 - x1)`

`- {24}^(2) = 2( - 6)(x2)`

`x2 = 48`

x2 is distance after slow down. now we should calculate distance of reaction time.

`d = tv`

`d = (1.2)(24) = 28.8`

d + x > 60 ==> he hits the deer. now calculate hit speed.

`{v2}^(2) - {24}^(2) = 2( - 6)(31.2)`

`{v2}^(2) = 201.6`