SOUND

Sounds are made when objects vibrate.
What is a vibration?

• a back-and-forth movement

• a circular movement

• an upward movement

Sound travels ______________ in water than it does in air.

• air

• faster

• heat

• slower

This is because the particles are closer together in ______________ than in ______________.

• water, air

• air, water

The particles can quickly pass on the ______________ from one particle to the next.

• heat

• slower

• vibrations

• water

What can happen when an object vibrates?

• It can make the air particles around it to vibrate.

• It does not affect the particles around it.

• The vibration can travel through different types of matter.

• 5  The vibration cannot travel through solids.

  A vacuum is a space without any air or other matter.

Explain why sound cannot travel through a vacuum.

• There is no gravity in a vacuum, so sound waves cannot move.
  
  
  

• There is no matter in a vacuum, so there are no particles to vibrate.

• Sound waves are too weak to move through empty space.

• A vacuum absorbs all sound waves, preventing them from traveling.

  Hassan plucks a rubber band. How does a rubber band produce sound when plucked?

• It releases air that creates sound waves.
  

• It vibrates, producing sound.
  

• It generates electricity that turns into sound.
  

• It changes color and emits sound.

  Hassan plucks a rubber band. How does sound travel from the vibrating rubber band to Hassan’s ear?

• The vibration of the rubber band makes air particles vibrate, and this vibration travels to Hassan’s ear.
  

• The rubber band releases sound waves that travel instantly without needing air.
  

• The rubber band creates an electric signal that reaches Hassan’s ear.
  

• The rubber band absorbs all surrounding sound, making it louder.

Fast vibrations make high-pitched sounds.

• true

• false

The pitch refers to how quiet or loud a sound is.

• true

• false