Question

A 25 kg mass is on a level, rough surface where the force of friction is a constant 15 N. A horizontal applied force of 65 N acts on the mass. The mass is initially at rest.

What speed does that mass have after being moved 2.0m?

Answer 1

V = sqrt(2aX)
where a is the acceleration and X is the distance it has moved from a stationary start.

The net force acting horizontally on the block is F = 50 N. Thus a = F/m = 50/25 = 2 m/s^2

V = sqrt(2*2*2) = sqrt8 = 2.83 m/s