A cart starting from rest rolls down a frictionless 1.0 m high hill. It travels a distance 2.0 m along the rough bottom surface until it comes to rest. What is the coefficient of kinetic friction along the bottom surface?
a. 4 m/s.
b. 0.5 m/s.
c. 25 m/s.
d. 7 m/s.
e. 6 m/s.

Option B is correct.

Explanation:

Given data

Height of the hill = AB = 1 m

Distance traveled  along the rough bottom surface = AC = 2 m

Now from the ΔABC

°

We know that  the coefficient of kinetic friction is

0.5

This is the value of the coefficient of kinetic friction

Thus option B is correct.

answer; (d) spontaneous processes are characterized by the overall conversion of order to disorder;