7th grade : Cambridge Science - Unit 6 Earth {hysics

Sound wave is ....

• things that vibrate

• things that move backwards & forwards quickly

• sounds travel from a vibrating things to our ears

• the force that we use to make am sound

Sounds are made by ...

• things that vibrate

• to move backwards & forwards quickly

• sounds travel from a vibrating things to our ears

• the force that we use to make am sound

To vibrate means ...

• things that vibrate

• to move backwards & forwards quickly

• sounds travel from a vibrating things to our ears

• the force that we use to make am sound

How fast is the speed of sound waves in the air?

• 10 m/s²

• 343 m/s

• 343 kg/hr

• 10 N/m

To hear a sound, there must be ...

• a vacuum air

• a medium containing particles which sound can travel

• a vibration of thing

• an isolator

Why we can not hear a sound in Moon?

Because there are no ....

• vibration of thing

• particle as medium for the sound travel

• sound loud enough to hear

• gravity

On this game, how can we hear the sound on the cup?

The sound wave travel through ....

• the cup

• the string

• the air

The uses of sonar, is a prove that ...

• sound can travel in water

• sound can not travel in water

• sound can be reflected

• sound can not be reflected

The reflection of a sound wave called ...

• reflux

• echo

• gravity

• chorus

Which of these statements are not the use of echo

• boat to detect location of fishes under the water

• bat use it to detect direction of insect

• geologist use it to calculate the height of a mointain

• doctor use it to make image of unborn baby inside mother's womb