Work and Kinetic energy-Practice Questions-Gr 9 & 10

1. A worker pushes a 1.50 × 103 N crate with a horizontal force of 345 N a distance of 24.0 m. Assume the coefficient of kinetic friction between the crate and the floor is 0.220.
a. How much work is done by the worker on the crate?
b. How much work is done by the floor on the crate?
c. What is the net work done on the crate?
2. If 2.0 J of work is done in raising a 180 g apple, how far is it lifted?
3. One of the world’s fastest helicopters, the Westland Lynx has a top speed of 4×102 Km/h. If the KE at this speed is 2.1×107 J. What is the helicopter’s mass?
4. A 7.00 kg bowling ball moves at 3.00 m/s. How fast must a 2.45 g table tennis ball move in order to have the same kinetic energy as the bowling ball? Is this speed reasonable for a table-tennis ball in play?
Work, energy and Power Playlist
intro (0:00)
Qc#1 (3:58)
Qc#2 (8:34)
KE-Qc#1 (11:30)
KE-Qc#2 (17:37)