The first two choices are wrong because force and work are two different physical quantities. The fourth choice depends upon the amount of friction.
The third choice is correct.
A box that is initially at rest is pushed by a person at an angle 0 with a force F until it reaches a speed of v. The coefficient of kinetic friction between the box and the surface is U.
Is this:
work done by person equal to magnitude of friction F
work done by person greater than mag of friction force
work of person greater than change of K energy of box
kinetic energy gained by box greater than energy dissipated by friction?
1 answer