Forces, work, energy, machines

Question 1 of 10

A boy of mass 50 kg climbs 4 m in 10 s (g = 10 m/s²). His power is

Question 2 of 10

A spring extends by 4 cm under a load of 8 N. Its spring constant is

Question 3 of 10

A uniform metre rule is balanced at the 50 cm mark. A 2 N weight at 20 cm is balanced by a weight at 80 cm of

Question 4 of 10

A lever has a load of 600 N at 0.2 m from the fulcrum. The effort needed at 1.2 m is

Question 5 of 10

A body of mass 2 kg is at a height of 10 m. What is its potential energy?

Question 6 of 10

A 1,200 kg car climbs a 20 m hill at constant speed in 40 s (g = 10 m/s²). The minimum power is

Question 7 of 10

A net force of 20 N acts on a 4 kg mass. The acceleration is

Question 8 of 10

A machine has a velocity ratio of 5 and an efficiency of 80%. Find its mechanical advantage.

Question 9 of 10

An inclined plane 5 m long raises a load 1 m. Its velocity ratio is

Question 10 of 10

A 50 kg boy climbs stairs 4 m high in 10 s (g = 10 m/s²). His power is