Work, energy and power

Question 1 of 10

A student of mass 60 kg runs up a flight of stairs of vertical height 15 m in 20 s. (g = 10 m/s²) (a) Calculate the work done against gravity. (b) Calculate the power developed. (c) Explain why the actual energy used by the student is greater. (d) State the energy changes involved.

Question 2 of 10

Find the kinetic energy of a 20 kg body moving at 2 m/s.

Question 3 of 10

At the highest point of a swinging pendulum, the energy is mainly

Question 4 of 10

Find the potential energy gained when a 50 kg mass is raised through 5 m. (g = 10 m/s²)

Question 5 of 10

A force of 100 N moves a box 2 m in its own direction. The work done is ___ J.

Question 6 of 10

A force of 100 N moves a box 10 m in its own direction. The work done is ___ J.

Question 7 of 10

Gravitational potential energy is given by

Question 8 of 10

The SI unit of work is the

Question 9 of 10

A force of 20 N moves a box 5 m in its own direction. The work done is ___ J.

Question 10 of 10

Find the potential energy gained when a 20 kg mass is raised through 2 m. (g = 10 m/s²)