PS: 7.3 Study Guide: Wave Interactions/Interference

An echo occurs because of wave

• interference.

• diffraction.

• diffraction.

• reflection.

If a wave strikes a barrier at a 45° angle, what is the angle of reflection?

• 180°

• 120°

• 90°

• 45°

Light is refracted when it

• strikes a barrier it cannot pass through.

• spreads around an obstacle such as a wall.

• passes from air to water at an angle.

• interferes with other waves.

What happens when a wave passes around a barrier that is shorter than its wavelength?

• The wave has a large angle of incidence.

• The wave spreads out around the barrier.

• The wave is refracted.

Constructive interference occurs when two waves pass through each other and the

• crests of both waves cancel each other out.

• crests of both waves have a smaller amplitude.

• crests of one wave overlap crests of the other wave.

• crests of one wave cancel out troughs of the other wave.

Reflected waves have the same speed as the original waves before they were reflected.

• True

• False

Diffraction occurs because waves travel at different speeds in different media.

• True

• False

You can hear sounds around the corner of a building because the sound waves are refracted.

• True

• False

Destructive interference decreases the amplitude of waves.

• True

• False

A standing wave forms when a wave is refracted.

• True

• False