A 47-kg box is being pushed a distance of 8.0 m across the floor by a force whose magnitude is 188 N. The force is parallel to the displacement of the box. The coefficient of kinetic friction is 0.24. Determine the work done on the box by each of the four forces that act on the box. Be sure to include the proper plus or minus sign for the work done by each force.

(a) 1504 J

(b) - 884.35 J

(c) 0 J

(d) 0 J

Explanation:

Mass, m = 47 kg

displacement, s = 8 m

Force, F = 188 N

Coefficient of friction = 0.24

(a) Work done by applied force

W = F s = 188 x 8 = 1504 J

(b) Work done by the friction force

W' = - 0.24 x 47 x 9.8 x 8 = - 884.35 J

(c) Work done by the gravitational force

W''= m g s cos 90 = 0 J

(d) Work done by the normal force

W''' = m g scos 90 = 0 J

a skateboard rolling across the street - apex

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach