A student stands 50 m in front of a building. He claps two blocks together and listens for the echo from the buildings. It takes 5.85 seconds to hear 20 echoes. What is the speed of sound?

• 171 m/s

• 341 m/s

• 1700 m/s

• 34 m/s

Which statement about a sound wave is correct?

• It can travel through a vacuum.

• It travels at a speed of 340 m/s in air.

• It cannot be reflected.

• It is transverse.

Which of the following statements best describes an echo?

• A sound that is refracted through a substance.

• A sound that has a large amplitude.

• A sound that has been reflected off a surface.

• A sound that is heard only in caves.

The oscilloscope trace shows a number of different sounds. Which of the sound waves will be the loudest?

• sound A

• sound B

• sound C

• sound D

The audible range of human hearing is said to range from 20 Hz to 20 000 Hz. What is meant by audible range?

• hearing

• the range that all animals and humans can hear

• the range which a speaker can generate

• the range of frequencies which humans can hear

Which of the following are properties of sound waves?

• They can be reflected.

• They can be refracted.

• They are longitudinal waves.

• All of the above.

Ships use sound waves to help them navigate the sea bed. Which of the following statements is not correct?

• Ships use echoes to calculate the depth of the sea.

• The speed of sound is faster in air than in water.

• This system of using echoes is called sonar.

• The sound waves reflect off the bottom of the sea bed

Which of the following materials can sound travel through?

• solids only

• solids and liquids

• solids, liquids and gases

• solids, liquids, gases and a vacuum

A sound wave has a frequency of 15 kHz. What is the time period of the wave?

• 6.67 × 10^-5 s

• 0.067 s

• 5100 s

• 15 s

Which of the following statements about sound waves is not correct?

• The angle of the reflected sound wave is smaller than that of the incident wave.

• Sound is passed on by vibrating particles.

• Sound can be used to find the depth of the sea bed using echoes.

• Sound is a longitudinal wave.