Assessment 2 2019

Question 1

What do waves do?

Answer 1

Waves transfer energy and information from one point to another through vibrations

Question 2

What is the word and symbol equation for wavespeed?

Answer 2

Wavespeed=Frequency X Wavelength

V= Fx(lamda)

Question 3

What is a transverse wave?

Answer 3

A wave in which the vibrations are perpendicular to the direction in which the wave travels

Question 4

What is a progressive

Answer 4

A disturbance moving from a source to surrounding places as a result of which energy is transferred from one point to another.

Question 5

Give 3 examples of transverse waves

Answer 5

1. Water waves
2. Secondary earthquake waves
3. All 7 regions of the EM spectrum

Question 6

What is a longitudinal wave?

Answer 6

A wave which the vibrations are parallel to the direction in which the wave travels.

Question 7

Give 3 examples of longitudinal waves

Answer 7

1. Sound waves
2. Ultrasound waves
3. Primary Earthquake waves

Question 8

Give 3 applications of echoes

Answer 8

1. Measuring the depth of water from a ship
2. Measuring to presence of fish beneath a fishing ship
3. Measuring the speed of a driver using a speed gun.

Question 9

What is sound produced by?

Answer 9

Vibrations

Question 10

What does sound need to pass through?

Answer 10

A medium

Question 11

What is the range of frequencies that can be heard by a human ear?

Answer 11

20Hz-20,000Hz

Question 12

What is a sound with a frequency of above 20,000Hz called?

Answer 12

Ultrasound

Question 13

Give two uses of ultrasound

Answer 13

Can be used to measure the foetal head diameter

Ultrasound can be used in industry to detect defects in metal

Question 14

What is the electromagnetic spectrum?

Answer 14

The electromagnetic waves are grouped into types that have similar wavelengths and so have similar properties.

Question 15

What are the properties of a mechanical wave?

Answer 15

Produced by a disturbance in a material medium

Made up of matter

Question 16

What are the properties EM (Electromagetic Wave)?

Answer 16

Made up for transverse waves
Made up of electric and magnetic fields
A wave produced by a disturbance in the form of a varying electric and magnetic field.

Question 17

What speed does EM waves travel at?

Answer 17

300,000,000 M/s

Question 18

What are the similarities of EM Waves?

Answer 18

They can all travel in a vacuum
They are all transverse waves
They all travel at the speed of light (300,000,000 M/s) in a vacuum

Question 19

What are the seven uses of Em waves

Answer 19

Radio waves-Bluetooth and radios in cars
Microwaves-Heating food and mobile phones
IR(infrared)-Sensors on cars for reversing
Visible light- Seeing things
UV-Detecting forged bank notes
X-ray- Detecting broken bones and fractures
Gamma- Used in medical imagine such as pet scans

Question 20

What are the five dangers of Electromagnetic (Em) radiation?

Answer 20

Microwave cause internal heating of body tissues
Infrared radiation is felt as heat and causes skin burns
Certain wavelengths of ultraviolet can damage skin cells and leas to cancer
Intense visible light can damage eyes
X rays and gamma rays damage cells, which may lead to cancer

Question 21

What are the four characteristics of the image formed by a plane mirror?

Answer 21

Same size
Same distance behind the mirror as the object is in front of the mirror
The image is virtual-(can not be projected by on to a screen)
The image is laterally inverted

Question 22

What is refraction?

Answer 22

The bending of light

Question 23

What are the two requirements for refractions

Answer 23

Must pass from one medium to another

Angle of incidence must be greater than 0 degrees

Question 24

What is Amplitude

Answer 24

The greatest displacement of the wave from its undisturbed positions. Unit-Metres

Question 25

What is wavelength

Answer 25

The distance between two consecutive crests or troughs. Unit-Metres