contestada

A 7.0kg ball is given an initial velocity of 14m/s and then is rolled along the floor. A friction force of 2.5N opposes its motion. For what length of time will it roll before stopping.

Respuesta :

a=F/m
=2.5/7.0
=0.36 m/s^2
The ball eventually stops, so the final velocity is 0 m/s.
t=(v-u)/a
=(14-0)/0.36
=38.9 s