Physics Practice Tests – Work, Energy and Power (Questions with Answers and Explanations)

Find the potential energy of an object of mass 10 kg placed on a building floor 10 m above the ground level. [g = 10 ms^-2] (JAMB 2017) 

A. 10,000 J   B. 5,000 J   C. 100 J   D. 1,000 J

An object of mass 20 kg is released from a height of 10 m above the ground level. The kinetic energy of the object just before it hits the ground is ____ [g = 10 ms^-2] (JAMB 2014)

A. 200 J   B. 4000 J   C. 2000 J   D. 500 J

A body is pulled over a distance of 500 m by a force of 20 N. If the power developed is 0.4 kW, calculate the time interval during which the force is applied.  (WASSCE  2011)

A. 0.2 s    B. 2.5 s   C. 25.0 s    D. 250.0 s

A body is pulled through a distance of 500 m by a force of 20 N. If the power developed is 0.4 kW, calculate the time for which the force acts. (WASSCE 2012)

A. 250.0 s     B. 25.0 s      C. 2.5 s      D. 0.5 s

A car travelling at 30 ms^-1 overcomes a frictional resistance of 100 N while moving. Calculate the power developed by the engine. [1 hp = 0.75 kw] (WASSCE 2014)

A. 0.23 hp      B. 0.40 hp      C. 4.00 hp      D. 4.40 hp