Given below are some examples of wave motion. State in each case if the wave motion is transverse, longitudinal or a combination of both
(i) Motion of a kink in a long coil spring, produced by displacing one end of the spring sideways.
(ii) Waves produced in a cylinder containing a liquid, by moving its piston back and forth.
(iii) Waves produced by a motor-boar sailing in water.
(iv) Light waves travelling from the sun to the earth.
(v) Ultrasonic waves in air, produced by a vibrating quartz crystal.

Explanation

(i) Transverse, because the displacement of the spring is at right angles to its length.
(ii) Longitudinal, because the piston is moving back and forth along the direction of propagation of wave.
(ii) Transverse and longitudinal.
(iv) Transverse.
(v) Longitudinal.