A 4kg block slides freely across a rough surface such that the block slows down with an acceleration of −1.25 m/s2 . What is the coefficient of kinetic friction between the block and the surface?

The coefficient of kinetic friction between the block and the surface is 0.127.

Explanation:

Given that,

The mass of a block, m = 4 kg

The acceleration of the block, a = -1.25 m/s²

We need to find the coefficient of kinetic friction between the block and the surface. The force of friction is given by :

So, the coefficient of kinetic friction between the block and the surface is 0.127.

no. dot product   =0 when vecs at right angles

the answer is a. hope this .