# If an object with a mass of #10 kg # is moving on a surface at #15 m/s# and slows to a halt after # 4 s#, what is the friction coefficient of the surface?

##### 1 Answer

Apr 27, 2017

#### Answer:

The coefficient of friction is

#### Explanation:

We start by calculating the deceleration.

We apply the equation of motion

The initial velocity is

The time is

The final velocity is

Therefore,

The acceleration is

According to Newton's Second Law, the frictional force is

So,

The normal force is

The coefficient of friction is