Work Done & Friction Flashcards

All 5 cards in this deck

What happens to an object when work is done against the frictional forces acting on it?

Its temperature rises.

Which energy store is filled when work is done against friction?

The thermal energy store of the object (and its surroundings).

True or false? Work done against air resistance causes a rise in temperature, just as work done against friction does.

True. Air resistance is a frictional force, so energy is transferred to thermal energy stores.

True or false? A car driving at a constant speed does no work, because its kinetic energy store does not change.

False. It still does work against air resistance and friction, transferring energy to thermal energy stores of the surroundings.

What effect does lubricating the moving parts of a machine have on work done against friction?

It reduces friction, so less work is done against friction and less energy is transferred to thermal energy stores.