Acceleration question? (Horizontal Kinematics)?

Question

A driver in a car traveling at a speed of

27.7m/s sees a deer 90.6 m away on the road.

Calculate the minimum constant acceler-

ation that is necessary for the car to stop

without hitting the deer (assuming that the

deer does not move in the meantime). Answer

in units of m/s2.

Answer 1

on this equation (velocity final)^2 - (Velocity initial)^2 = 2(acceleration)(distance)

final velocity when at stop is = 0

then substitute:

(o)^2 - (27.7)^2 = 2(acceleration)(90.6)

766.29/(181.2) = acceleration

-4.22 m/s^2 = acceleration

since it is negative, then it is considered deceleration

deceleration = 4.22 m/s2

email me if you want to ask more