04 Wave basics and EM spectrum

Question 1

Define Amplitude

Answer 1

The distance from the equilibrium position to the maximum displacement

Question 2

Define Wavefront

Answer 2

A line joining points on a wave at the same point in their wave cycle at a given time

Question 3

Define Frequency

Answer 3

the number of waves that pass a single point on one wave and the same point on the next wave

Question 4

Define wavelength

Answer 4

the distance between a point on one wave and the same points on the next wave

Question 5

Time period

Answer 5

the time takes for one complete wave to pass a fixed point

Question 6

name the equation linking speed, wavelength, and frequency

Answer 6

speed = frequency*wavelength
v=fλ

Question 7

How do you find the frequency of a wave when give the time period?

Answer 7

frequency = 1/time period
f=1/T

Question 8

What is a wave front?

Answer 8

a line joining points on a wave at the same point in their wave cycle (e.g. all peaks)

Question 9

List the order of the magnetic spectrum:

Answer 9

Radio
Microwave
Infrared
Visible
Ultraviolet
X-Ray
Gamma ray

Question 10

Which of the following has the highest frequency:
Ultraviolet; Infrarea; Gamma; Radio

Answer 10

Gamma

Question 11

Which of the following has the lowest frequency: Gamma; X-ray; Microwave; Visible

Answer 11

Microwave

Question 12

State 2 uses of Radio waves:

Answer 12

• Radio and TV communications
• Radar (like aeroplanes, etc)

Question 13

State 2 uses of Microwaves:

Answer 13

• Satellite transmissions
• Cooking
• Radar system uses
• WiFi

Question 14

State 2 uses of Infrared waves:

Answer 14

• heaters
• night vision eqipment

Question 15

State 2 uses of Visible light:

Answer 15

• fibre obtics
• photography

Question 16

State 2 uses of Ultraviolet:

Answer 16

• flourescent lamps
• To detect forgeries

Question 17

State 2 uses of X-rays

Answer 17

• medical imaging
• security (because they have a very short wavelength and a high frequency, they can penetrate material easily)

Question 18

State 2 uses of Gamma waves:

Answer 18

• Steriling food
• steriling meidal equipment

Question 19

Name a danger of microwaves

Answer 19

internal heating (of body tissues)

Question 20

Name a danger of infrared waves:

Answer 20

skin burns

Question 21

Name a danger of ultraviolet waves:

Answer 21

• skin cancer
• blindness
  (can be prevented by wearing sunglasses; suncream)

Question 22

Name a danger of X-rays:

Answer 22

mutation/damage to cells in the body

Question 23

Name a danger of Gamma rays:

Answer 23

• mutation of cells
• cancer

Question 24

Why can’t you use atstronomy as an example for any of the waves in the EM spetrum?

Answer 24

As atstronomy takes place over the entire EM spectrum

Question 25

What do all of the waves on the EM spectrum travel at?

Answer 25

Speed of light (300 000 000 m/s) or (300 x10^6)

Question 26

List three scalars:

Answer 26

Any from the following list: - Mass (kg) - Temperature (k) - DIstance (m) - Time (s) - Speed (m/s) - energy (J) - density (km/m^3) - frequency (Hz) - area (m^2)

Question 27

List three Vectors:

Answer 27

Any from the following list: - Force (N) - Displacement (m) - Velocity (m/s) - Acceleration (m/s^2) - momentum (kg m/s) - weight (kg) - impulse

Question 28

What is the speed of light?

Answer 28

300 000 000 m/s or 300 *10^6 m/s

Question 29

What is Newton's second law?

Answer 29

force = mass * acceleration

Question 30

What happens if the surface area of an object increases when it falls?

Answer 30

Larger surface area increases air resistance Lowers terminal velocity.

Question 31

what angle is the oscillation of a transverse wave to the wave direction?

Answer 31

90*

Question 32

what angle is the oscillation of a longitudinal wave to the wave direction?

Answer 32

parallel

Question 33

a transverse wave is 1 type of wave. Name the other kind of wave

Answer 33

longitudinal

Question 34

name the 2 types of waves:

Answer 34

longitudinal and transverse

Question 35

what is frequency?

Answer 35

the number of waves per second

Question 36

what speed do all fo the waves on the EM spectrum travel at?

Answer 36

300 000 000 m/s; speed of light

Question 37

Name the 7 waves on the EM spectrum, starting from the lwest frequency to the highest frequency.

Answer 37

Radio; Microwave; Infrared; Visible light; UV; X-ray; Gamma ray