A student is investigating the idea of power while pushing a laboratory trolley along…
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A student is investigating the idea of power while pushing a laboratory trolley along a smooth floor.
(i) State what is meant by the term power and write its SI unit.
(ii) While the trolley moves with uniform velocity, the student claims that the rate at which she does work depends on both the force she applies and the speed of the trolley. Explain this statement qualitatively without using any numerical calculation.
(iii) The same trolley-pushing arrangement is now operated by a motor that works at a constant power. If the speed of the trolley is doubled, describe and justify what happens to the magnitude of the horizontal force that the motor can exert on the trolley.