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

Answer:

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

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

$x2 = 48$

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.

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

${v2}^{2} = 201.6$