A force of 5.0 N moves a 6.0 kg object along a rough floor at a constant speed of
2.5 m/s. (a) How much work is done in 25 s.?
(b) What power is being used? (c) What force of friction is acting on the object?
The power delivered by the 5 N force to keep the object moving at a constant speed of 2.5 m/s is given by,
P = Fv = (5)(2.5) = 12.5 W
We know rate of workd done is power, so, P = W/t
=> W = Pt = (12.5)(25) = 312.5 J
Since, the force is unable to accelerate the object, that means the frictional force is equal to the force applied. So, frictional force = 5 N