A student wearing frictionless in-line skates on a horizontal surface is pushed by a friend with a constant force of 47 N. How far must the student be pushed, starting from rest, so that her final kinetic energy is 354 J?

7.53 m

Explanation:

Force, F = 47 N

initial velocity, u = 0

Final kinetic energy, Kf = 354 J

Let the distance traveled by the student is s.

According to the work energy theorem,

Work done by all forces = Change in kinetic energy

Force x distance = final kinetic energy - initial kinetic energy

F x s = kf - ki

47 x s = 354

s = 7.53 m