Unit 3

Question 1

Which way does light refract when passing from air to glass?

Answer 1

TOWARDS the normal (r<i)

Question 2

Which way does light refract when passing from glass to air?

Answer 2

AWAY from the normal (r>i)

Question 3

How does a LONGITUDINAL wave move?

Answer 3

In longitudinal waves, the particles vibrate in the same direction as the direction travel.

Question 4

How does a TRANSVERSE wave move?

Answer 4

In transverse waves, the particles vibrate in right angles to the direction travel.

Question 5

When will you see circular waves in diffraction?

Answer 5

When the gap that the waves pass through is smaller than the actual wavelength of the waves.

Question 6

Name all waves in the Electromagnetic Spectrum.

Answer 6

Radio & TV
Microwaves
Infrared
Visible Light
Ultraviolet
X-rays
Gamma Rays

Question 7

Give an example of an application for every wave type in the EM spectrum.

Answer 7

Radio & TV - Used for broadcasting
Microwaves - Radar technology
Infrared - Used for TV remotes
Visible Light - Makes things visible
UV - Suntan lamps
X-ray - Medical Imaging
Gamma Rays - To kill cancer cells

Question 8

What is the law of reflection?

Answer 8

Angle of Incidence (i) = Angle of Reflection (r)

Question 9

What is the principle of reversibility?

Answer 9

Light always travels in a straight line. If the direction of the ray of light is reversed, it will follow the same path, but in the opposite direction.

Question 10

Give an example of a longitudinal wave.

Answer 10

Sound Waves

Question 11

Give an example of a transverse wave.

Answer 11

Electromagnetic spectrum.

Question 12

What is diffraction?

Answer 12

Diffraction is where a wave bends into the shadow region when passing an obstacle.

Question 13

What is refraction?

Answer 13

Refraction is the change in speed of light when it passes from one medium to another. This results in a change in wavelength.

Question 14

What do you call the part of a wave between the axis and crest/trough?

Answer 14

Amplitude

Question 15

Define amplitude.

Answer 15

The distance between the trough/crest and the axis.

Question 16

What is the crest?

Answer 16

The highest point of a wave.

Question 17

What is the trough?

Answer 17

The lowest point of a wave.

Question 18

What is the frequency of a wave?

Answer 18

How many times a wave passes a point within a second.

Question 19

What is the wavelength of a wave?

Answer 19

The distance between 2 troughs/crests

Question 20

What is the wave speed of a wave?

Answer 20

How far a wave travels in a second.

Question 21

What is the period? (T)

Answer 21

The time taken for a wave to pass a point.

Question 22

What is the formula for period?

Answer 22

Time taken / Number of events

Question 23

Which wave in the EM spectrum has the largest wavelength?

Answer 23

Radio & TV waves

Question 24

Which wave in the EM spectrum has the smallest wavelength?

Answer 24

Gamma rays

Question 25

Which wave in the EM spectrum has the highest frequency?

Answer 25

Gamma rays

Question 26

Which wave in the EM spectrum has the lowest frequency?

Answer 26

Radio & TV waves

Question 27

What does MICRO mean?

Answer 27

10^-6

Question 28

What does MILLI mean?

Answer 28

10^-3

Question 29

What does KILO mean?

Answer 29

10^3

Question 30

What does MEGA mean?

Answer 30

10^6

Question 31

What does GIGA mean?

Answer 31

10^9

Question 32

What quantity is speed?

Answer 32

Scalar — Direction is not important

Question 33

What quantity is velocity?

Answer 33

Vector — Direction is important

Question 34

What quantity is weight?

Answer 34

Vector — It has a magnitude and direction

Question 35

What is a magnitude?

Answer 35

Magnitude is how much there is of something, or how large something is, but not which direction it moves in.

Question 36

What is a vector quantity?

Answer 36

A quantity which has both a magnitude and direction.

Question 37

What is a scalar quantity?

Answer 37

A quantity which has a magnitude, but no direction

Question 38

What is the formula for calculating average speed?

Answer 38

Average Speed = total Distance/total Time

Question 39

What is the formula for calculating instantaneous speed?

Answer 39

Instantaneous Speed = Very small Distance / Very short Time

Question 40

What is the formula to calculate power rating?

Answer 40

P = IV P = E/t

Question 41

When would the formula for gravitational potential energy be used?

Answer 41

When something is subjected to gravity (ie. when a mass is being lifted)

Question 42

What is the formula for gravitational potential energy?

Answer 42

E = mgh ——— E = Gravitational Potential Energy (J) g = Gravitational Field Strength (Nkg-1) h = Height (m)

Question 43

When a satellite orbits a planet, what stays constant?

Answer 43

The horizontal speed of the satellite

Question 44

Does a satellite move when orbiting a planet?

Answer 44

No (don't ask why)

Question 45

Is a satellite weightless when orbiting a planet?

Answer 45

No.

Question 46

What is the speed of light?

Answer 46

3x10^8

Question 47

What is distance?

Answer 47

Distance (d) is the total length of the path traveled by an object, regardless of direction. - It is a scalar quantity (has only magnitude) - Unit: Meters (m). - Always positive and never decreases.

Question 48

What is displacement?

Answer 48

Displacement (S) is the shortest straight-line distance from the starting position to the final position, with a specific direction. - It is a vector quantity (has both magnitude and direction). - Unit: Meters (m). - Can be positive, negative, or zero depending on direction.