Waves

All waves fall into one of two categories. What are they?

• Sound waves

• Light waves

• Longitudinal waves

• Transverse waves

Waves are generated by particle vibrations.

• True

• False

Which statement describes a longitudinal wave?

• Particles vibrate in the same direction as the wave.

• Particles vibrate 90° to the direction of the wave.

Which statement describes a transverse wave?

• Particles vibrate in the same direction as the wave.

• Particles vibrate 90° to the direction of the wave.

Which one of these statements is wrong?

• In longitudinal waves, the wave vibrates in the same direction as the particles.

• In longitudinal waves, the particles vibrate in the same direction as the wave.

Answer explanation

It is the particle that does the vibrating; not the wave.

Select all the longitudinal waves.

• Light waves

• Sound waves

• P-waves

• S-waves

Select all the transverse waves.

• Light waves

• Sound waves

• P-waves

• S-waves

What can happen to a wave when it hits a boundary?

• It can be absorbed.

• It can be reflected.

• It can be refracted.

• It can be transmitted.

Answer explanation

All four things can happen.

When a wave goes from one medium (substance) into another, what happens all the time?

• It changes direction.

• It slows down.

• It speeds up.

• It changes speed.

Answer explanation

The only thing that happens all the time is that it changes speed.

If the wave comes in at the normal, it will not change direction.

Waves can speed up or slow down, depending on the substance.

So, the only thing that happens all the time is that it changes speed.

What is the name of the imaginary line that is drawn 90° to the interface?

• The ray of reflection.

• The ray of refraction.

• The normal.

• The perimeter.