# Part 1

A 15.6 kg block is dragged over a rough, hor-

izontal surface by a constant force of 72.2 N

acting at an angle of angle 34.8� above the

horizontal. The block is displaced 24.6 m and

the coefficient of kinetic friction is 0.234.

Find the work done by the 72.2 N force.

The acceleration of gravity is 9.8 m/s2 .

Answer in units of J.

Part 2

Find the magnitude of the work done by the

force of friction.

Answer in units of J.

part 3

What is the sign of the work done by the

frictional force?

1. negative

2. zero

3. positive

part 4

Find the work done by the normal force.

Answer in units of J.

part 5

What is the net work done on the block?

Answer in units of J.