Question

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.

Answer 1

Answer:

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

$\sin \theta = \frac{AB}{AC}$

$\sin \theta = \frac{1}{2}$

$\theta = 30$ °

We know that  the coefficient of kinetic friction is

$\mu = \tan \theta$

$\mu = \tan 30$

$\mu =$ 0.5

This is the value of the coefficient of kinetic friction

Thus option B is correct.