A student stands a distance x in front of a large wall. He claps his hands at a regular rate so that each clap coincides with the echo from the previous clap. In a time t, he claps his hands N times. Which expression is used to calculate the speed of sound in air?

A flash of lightning and the corresponding sound of the thunder are detected 6s apart. A student calculates that the …

The displacement-distance and displacement-time graphs are for a water wave in a ripple tank. What is the speed of th…

Which application may use the part of the electromagnetic spectrum called microwaves?

The ray diagram shows two rays from a point on an object placed in front of a diverging (concave) lens. What are the …

Which list contains an example of a non-magnetic material, a magnetic material and a magnetised material?

To charge an isolated metal sphere by induction, the following four processes are required. P The sphere is earthed b…