Physics: Work, Kinetic Energy, and Energy Lost to Friction

Question

A 1.00-kg block is pushed along a rough horizontal floor with a horizontal force of 5.00 N for a distance of 5.00 m. If the block is moving at a constant velocity of 4.00 m/s, find...

1. The work done on the block by the force
2. The kinetic energy of the block
3. The energy lost to friction

Answer 1

1.

Work done by the force = force x displacement = 5x5 = 25J

2.

KE of block = 1/2 Mv²

  1/2 x 1 x 4x 4 = 8 J

3.

Energy lost = 25 - 8 = 17 J