Question

The waves produced by a motor boat sailing in water are
A. Transverse
B. Longitudinal
C. Longitudinal and transverse
D. Stationary

Answer 1

Transverse waves are waves in which all the points in the wave oscillate in a direction perpendicular to the direction of propagation of the wave.Longitudinal waves are waves in which all the points oscillate in the direction of propagation of waves.

Complete answer:
To get a clear idea about the transverse and longitudinal wave let us look at the picture below. When a string is taken and a wave is produced we can see that there are crests and troughs formed. On the other hand if a spring is given a wave we see that compression and expansions are formed indicating longitudinal waves.

When the motor boat moves on the surface of water it produces waves on the surface due to which the boat is able to move forward. This is possible only when the waves are transverse. Because transverse waves are the waves in which the particles of waves move in a motion perpendicular to the boat or direction of propagation of the wave.

Hence it moves forward.The motor boat moves forward pushing the water in the front towards the back. This creates disturbance in water on its surface. But on the other hand due to vibrations inside water(inside its surface ) longitudinal waves are produced.

Hence, the correct answer is option C.

Note: There is a misconception that water waves push water from one direction to another, in fact the particles of water actually stay at a place. They appear to move up and down due to energy variation. The energy propagates through water, but the water stays at the same place as before.