1 A block \(B\) of mass 3 kg moves with deceleration \(1.2 \mathrm {~m} \mathrm {~s} ^ { - 2 }\) in a straight line on a rough horizontal surface. The initial speed of \(B\) is \(5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). Calculate
- the time for which \(B\) is in motion,
- the distance travelled by \(B\) before it comes to rest,
- the coefficient of friction between \(B\) and the surface.