Sound and light chp. 9

Question 1

Luminous

Answer 1

releasing their own light

Question 2

Non-Luminous

Answer 2

not releasing their own light, only reflecting light from nearby sources.

Question 3

Transparent

Answer 3

a substance that allows light to pass through it. Objects can be seen clearly through transparent materials.

Question 4

Translucent

Answer 4

allows light to come through imperfectly, as in frosted glass.

Question 5

Opaque

Answer 5

does not allow light to go through the material.

Question 6

Reflection

Answer 6

bouncing of the surface of a substance.

Question 7

Refraction

Answer 7

change in the speed of light as it passes from one substance to another.

Question 8

Concave

Answer 8

curved inwards.

Question 9

Convex

Answer 9

curved outwards.

Question 10

Converging

Answer 10

moving towards one another.

Question 11

Diverging

Answer 11

moving further away from each other

Question 12

Tranverse wave

Answer 12

wave involving the vibration of the particles perpendicular to the direction of energy transfer.

Question 13

Longitudinal or compression wave

Answer 13

a wave involving the movement of the particles in the same direction as energy transfer

Question 14

Wavelength

Answer 14

the distance from neighbouring crests or troughs on a wave. This is the distance between two particles that are vibrating in step.

Question 15

Amplitude

Answer 15

the maximum distance that a particle moves away from its undisturbed position.

Question 16

Frequency of a wave

Answer 16

the number of waves moving passed a point per second. (Measured in Hertz).

Question 17

Electromagnetic spectrum

Answer 17

complete range of electromagnetic wavelengths of energy radiated as electric and magnetic fields.

Question 18

Echolocation

Answer 18

use of sound to locate something by detecting the echoes.

Question 19

Ultrasound

Answer 19

sound with frequencies too high for humans to hear.

Question 20

Pitch

Answer 20

highness or lowness of sound. Depends on the frequencies of the sound.