What are waves?
4 marks · NormalA student throws a pebble into a still pond and observes waves spreading out from the point where the pebble lands.
State what is transferred by the water waves across the pond.
Describe what happens to the water itself as the waves move outward from the point of impact. Do the water particles move from the centre to the edge of the pond?
Give one example, other than water waves, where waves are used to transfer information.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Energy (and information)
(b) Water vibrates/oscillates up and down but does not travel with the wave; the water stays roughly in the same place.
(c) (Examples: radio waves, sound waves, light used in fibre optics, etc.)
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States energy or information is transferred by the wave.
B2 (b) · 1 mark · Describes water moves up and down/vibrates/oscillates.
B3 (b) · 1 mark · States water does NOT move across pond with the wave (remains in place).
B4 (c) · 1 mark · Gives a correct example (not water waves), e.g., sound waves, radio waves, light waves, etc.
Worked solution
a) Energy (or information) is transferred by the water waves.
b) The water itself moves up and down (oscillates) as the wave passes, but does not travel outward from the centre; the water stays roughly in the same place.
c) Example: Sound waves (used in telephones); or Light waves in fibre-optic cables; or Radio waves for broadcasting information.