Every card in Waves, light and sound, Year 7: more practice
The whole deck, in order — so you can read it through before your child ever sees it.
- Why do we see lightning before we hear the thunder?
Light travels much faster than sound
HintCompare the two speeds.
WhyLight travels at about 300 000 000 m/s, but sound travels at about 340 m/s in air.
- A ray of light hits a plane mirror with an angle of incidence of 35°. What is the angle of reflection in degrees? (number only)
35
HintThe law of reflection.
WhyThe angle of incidence equals the angle of reflection, measured from the normal.
- Why does a smooth mirror form a clear image while a rough wall does not?
The mirror reflects light in one direction
HintCompare how rays bounce off the two surfaces.
WhyA smooth surface reflects the rays in a regular way, but a rough surface scatters them in all directions.
- A struck tuning fork is touched on the surface of water and splashes appear. What does this show?
The fork is vibrating
HintWhat is happening to the prongs when it makes a sound?
WhySounds are made by vibrations. The splash shows the fork is moving quickly to and fro.
- Which part of a drum vibrates to make its sound?
The drum skin
HintIt is the part you hit.
WhyHitting the skin makes it vibrate, and it makes the nearby air vibrate.
- A string vibrates 1200 times in 6 seconds. What is its frequency in hertz? (number only)
200
HintFrequency is the number of vibrations per second.
Why1200 ÷ 6 = 200 Hz.
- A guitar string is pressed so that the vibrating part is shorter. Does the note get higher or lower?
Higher
HintThink about which string vibrates faster.
WhyA shorter string vibrates faster, so its frequency is higher.
- Loudness of sound is measured in ____.
decibels
HintThe unit is named after Alexander Graham Bell.
WhySound level, or loudness, is measured in decibels using a sound level meter.
- A drum is struck harder. What changes about the sound waves?
Their amplitude increases
HintWhich property of a wave means the size of the vibration?
WhyA harder hit makes bigger vibrations, so a greater amplitude and a louder sound. The pitch stays the same.
- Sound usually travels fastest in solids and slowest in gases. Why?
The particles in a solid are closer together
HintThink about how vibrations pass from one particle to the next.
WhyClose-packed particles pass vibrations on to their neighbours more quickly than those far apart in a gas.
1★ KS3-PHYS-WAV-0036
2★ KS3-PHYS-WAV-0037
3★ KS3-PHYS-WAV-0038
4★ KS3-PHYS-WAV-0039
5★ KS3-PHYS-WAV-0040
6★ KS3-PHYS-WAV-0041
7★ KS3-PHYS-WAV-0042
8★ KS3-PHYS-WAV-0043
9★ KS3-PHYS-WAV-0044
10★ KS3-PHYS-WAV-0045
Keep what you learn
Here, nothing is saved. In your child’s own sky every card is scheduled — it comes back just before they’d forget it — and the professor who wrote it is one tap away.