# A hockey puck is hit on a frozen lake and starts moving with a speed of 12.0 m/s. Exactly 5.0 s later, its speed is 6.0 m/s. What is the puck’s average acceleration, and what is the coefficient of kinetic friction between puck and ice?

##### 1 Answer

Average acceleration is

#### Explanation:

Average deceleration

So,

Now, if this happened due to frictional force then we can say that the frictional force acting was

where

So, the deceleration caused by the force is

And this is equal to

Putting