Forces, work, energy, machines

Question 1 of 10

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

Question 2 of 10

A 2 kg ball moving at 6 m/s collides head-on with a stationary 4 kg ball. If they stick together, the kinetic energy lost is

Question 3 of 10

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

Question 4 of 10

The coefficient of friction is 0.4 for a 50 N block on a level floor. The limiting friction is

Question 5 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 6 of 10

A 5 kg block on a horizontal surface needs 20 N to move it at constant speed (g = 10 m/s²). The coefficient of friction is

Question 7 of 10

A pulley system with 4 supporting strands has a velocity ratio of

Question 8 of 10

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

Question 9 of 10

A body floats in water because

Question 10 of 10

A 60 kg boy climbs stairs 5 m high in 10 s. What is his power?