A ship that is stationary on the surface of the sea sends pulses of sound vertically downwards towards the sea bed. Each pulse that reflects from the sea bed is received 1.0s after it is sent out. A whale swims under the boat and a pulse is received 0.60 s after it is sent out. The speed of sound in sea water is 1500 m/s. What is the distance of the whale above the sea bed?

Below are four statements about the uses of electromagnetic radiation. Gamma rays are used in medical treatment. Infr…

A ripple tank is used to show wave behaviour. The dipper vibrates up and down at a constant frequency. What happens t…

A wave has a frequency of 10 kHz. Which pair of values of its speed and wavelength is possible?

A small emergency generator supplies 432 000 000 J of electrical energy in twenty-four hours. What is the average pow…

The liquid in a puddle evaporates and this causes its temperature to change. How does the temperature of the liquid c…

When a refrigerator is switched on for the first time, the air surrounding the ice-box is cooled. What happens to the…