Topic 4

Question 1

How do waves transfer energy

Answer 1

Waves transfer energy without transferring matter

The waves move but not the particles

Question 2

Wavelength

Answer 2

Distance between the same points on two consecutive waves

Question 3

Amplitude

Answer 3

The height of waves from the line

Waves with more energy- higher amplitude

Question 4

Frequency

Answer 4

Number of waves which pass a single point per second

Question 5

Period

Answer 5

The time taken for a wave to completely pass a single point

Question 6

Wave front

Answer 6

The direction of the wave

Question 7

What does v = f × lamda mean

Answer 7

Wave Speed = frequency x wave length

Question 8

What happens if you increase velocity

Answer 8

Increases frequency

Question 9

What happens if you make the period smaller

Answer 9

Higher frequency
Greater velocity

Question 10

Examples of transverse waves

Answer 10

Light , seismic waves , water

Question 11

Examples of longitudinal waves

Answer 11

Sound waves , seismic p waves

Question 12

Ehat is a transverse wave

Answer 12

A wave where the vibrations are at right angles , perpendicular, to the direction of wave travel
I. I. I
I. I. I. I. I
I. I. I. I. I
I. I. I

Question 13

What is a longitudinal wave

Answer 13

wave that moves in the same direction as the direction in which the particles are vibrating
IIIL. IIII. III
II. IIIII. IIII

Question 14

How to measure speed of sound in air

Answer 14

1. Stand 50 m from wall and make noise
2. Have to microphones connected to a data logger and record the time it takes to pass from one to other
   3.use speed = distance ÷ time

Question 15

What is refraction

Answer 15

When waves pass from a medium to a denser medium (air and glass)
It causes the wave to refract

Question 16

What happens when a wave refracts?

Answer 16

The wave will refract at the boundary and will change direction to go towards the normal
Speed decreases
Wavelength decrease

Question 17

What is reflection

Answer 17

Waves only reflect off flat surfaces

Question 18

Features of reflection

Answer 18

The smoother the surface the better the reflection
Rough surfaces may scatter the light
Angle of incidence = angle of relections
Electrons absorb light energy and emmit it as a reflected wave

Question 19

What happens when you hear a noise?

Answer 19

1. Outer ear collects sound an channels it down ear canal
2. The sound waves hit eardrum
3. Eardrum vibrates at same frequency as sound wave
4. The small bones vibrate at same frequency

Question 20

What happens after you hear a noise ?
After small bones vibrate at same frequency as eardrum

Answer 20

1. Vibrations of small bones transferred to fluid in the inner ear called the cochlea
2. Small bones act as an amplifier
   3.as the fluid moves due to compression waves the small hairs in the cochlea move too
   4.each hair can detect a specific frequency
3. When that frequency is detected it sends signals to the brain

Question 21

How to scan for fetuses

Answer 21

An infrasound wave creates an image of the foetus because they partially reflect at each surface

Question 22

Uses of electromagnetic spectrum

Answer 22

Radio- communication,
Microwave- cooking
IR - thermal imaging
Uv - security marking
X rays- pbserveing internal structure of objects
Gamma - sterilising food equipment