P4.2 Frequency is measured in _______.

• Hertz (Hz)

• Meters per second (m/s)

• Meters (m)

• Decibels (Db)

P4.2 Which wave in the diagram has the greatest frequency?

• 1

• 2

• 3

• 4

P4.3 What two parts make up a longitudinal wave?

• Compressions and rarefactions
• Crests and troughs
• Compressions and crests
• Rarefactions and troughs

P4.3 Sound travels fastest in...

• Solids

• Liquids

• Gases

• Air

P4.2 The volume of a sound is measured in units called ________

• Decibels (Db)

• Litres (L)

• Hertz (Hz)

• Amps (A)

P4.3 Why is sound able to travel faster through a solid than a gas?

• Gas molecules are packed tightly.
• Sound does not travel faster through a solid than a gas.
• Solid molecules are packed tightly.
• Gas molecules move slowly.

P4.4 Why do we see lightning before we hear the thunder?

• Our eyes trick us
• Light travels faster than sound in air

• Lightning and thunder are different things

• We see lightning and hear thunder at the same time

P4.1 What do waves transfer?

• Just matter

• Just energy

• Energy and matter

• Neither energy nor matter

P4.8 A camera's aperture is similar to the _______ in the human eye

• Ciliary muscles

• Pupil

• Iris

• Retina

P4.8 What part of the human eye focuses light?

• Pupil

• Retina

• Iris

• Lens