1.1. Waves can travel on water, through air or in a vacuum.

The diagram shows the side-view of a wave on the surface of water.

Each square on the grid represents 1 cm x 1 cm. 

 (i) State the wavelength of the wave shown. 

(1)

(ii) On the grid sketch the trace of a wave travelling at the same speed, but with a larger amplitude and a lower frequency.  

(2)

1.2. Two students investigate the speed of sound waves in air.

They use a stopwatch that shows times to the nearest 0.1 s.

They use an outdoor running track as their measure of distance.

The track is straight and 100 m long.

Describe what else they must do to obtain a value for the speed of sound. 

1.3. (i) State the equation linking wave speed, frequency and wavelength. 

 (1)

(ii) The speed of radio waves is 300 000 000 m/s.

A radio wave has a frequency of 31 MHz. Calculate the wavelength of this radio wave.  

(3)

 wavelength = .......................... 

1.4. A sound wave and a radio wave have the same wavelength.     

State why they have different frequencies.