Practice Work in Physics
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
The transfer of energy that occurs when a force causes an object to move through a distance in the direction of the force, calculated as the dot product of force and displacement vectors.
Energy transferred by pushing something through space — force and displacement must both be present.
Example 1
easyA person pushes a box with a force of 50 \text{ N} over a distance of 10 \text{ m} in the direction of the force. How much work is done?
Example 2
mediumA person pulls a sled with 100 \text{ N} at 30° above the horizontal for 20 \text{ m}. How much work is done?
Example 3
mediumA 5 \text{ kg} box is lifted 3 \text{ m} vertically at constant speed. How much work is done by the lifting force? Use g = 9.8 \text{ m/s}^2.
Example 4
hardA child pushes a 20 \text{ kg} crate 8 \text{ m} across a floor with a 60 \text{ N} horizontal force. Friction exerts 40 \text{ N} opposing the motion. What is the net work done on the crate?