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

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a). Work done = F * displaement in the direction of force = 5 * (25*2.5)=312.5 NM

b).Power used = Force *vel = 5* 2.5 = 12.5 NM/sec

c). Force of friction = 5 N in opposite direction as there is no acceleration, hence net force on object should be zero.

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