P11 Glossary

Question 1

Amplitude

Answer 1

the height of a wave crest or trough of a transverse wave from the rest position. For oscillating motion, the
amplitude is the maximum distance moved by an oscillating object from its equilibrium position

Question 2

Compression

Answer 2

squeezing together

Question 3

Electromagnetic waves

Answer 3

electric and magnetic disturbances that transfer energy from one place to another

Question 4

Frequency

Answer 4

the number of wave crests passing a fixed point every second

Question 5

Longitudinal waves

Answer 5

waves in which the vibrations are parallel to the direction of energy transfer

Question 6

Mechanical wave

Answer 6

vibration that travels through a substance

Question 7

Oscillate

Answer 7

move to and fro about a certain position along a line

Question 8

Rarefaction

Answer 8

stretched apart

Question 9

Reflection

Answer 9

the change of direction of a light ray or wave at a boundary when the ray or wave stays in the incident
medium

Question 10

Refraction

Answer 10

the change of direction of a light ray when it passes across a boundary between two transparent substances
(including air)

Question 11

Speed

Answer 11

the speed of an object (metres per second) = distance moved by the object (metres) ÷ time taken to move the
distance travelled (seconds)

Question 12

Transmission/transmitted

Answer 12

a wave passing through a substance

Question 13

Transverse wave

Answer 13

a wave where the vibration is perpendicular to the direction of energy transfer

Question 14

Vibrate

Answer 14

oscillate (move to and fro) rapidly about a certain position

Question 15

Wavelength

Answer 15

the distance from one wave crest to the next