Physics - Recall for Chapter 5: Work, Energy and Power
OCR A-Level Physics 2022
Recall Questions
Work done
Define work done (energy transferred by a force)?
Work done = Force x distance moved in _ _ direction of force _ _
How much work is done on an object by a force acting at right angles to the direction of motion of an object?
None.
Power and its units
Define the Joule?
Work done to move a force of $1N$ (through) a distance of $1m$ through the point of application.
Conservation of energy and efficiency
State the principle of the conservation of energy?
Energy cannot be created or destroyed; it can only be transferred/transformed.
Why are energy transfers in the real world not 100%?
The efficiency of a device is always less than 100% because of heat losses due to friction/air resistance.