Physics Help

Question

Georgie was pulling her brother (of mass 23.5 kg) in a 11 kg sled with a constant force of 39 N for one block (56 m). How much work did Georgie do? Answer in units of J.

Part 2: How long would a 100 W lightbulb have to glow to produce the same amount of energy expended by Georgie? Answer in units of s.

Answer 1

Part 1:

Georgie was pulling her brother with a constant force is .

The sled moves distance is .

The component of force that is in the direction of the sleds movement is .

The work done is .

Substitute and .

.

The work done by Georgie is .

Answer 2

Part 2:

The power of the light bulb is .

From Part 1: The work done by Georgie is .

The power is .

The time .

Substitute and .

.

light bulb needs to glow .