physics

Question 1

Do you always need units in physics answers

Answer 1

yes

Question 2

weight:

Answer 2

Force of gravity

Question 3

what is an advantage of an oil power station

Answer 3

It is more reliable, not dependent on weather

Question 4

weight equation

Answer 4

w=mg

Weight = mass x gravity

Question 5

pressure equation

Answer 5

P = F/A
Pressure = force/area

Question 6

density equation

Answer 6

P = m/v

Density equals mass/volume

Question 7

describe the movement of molecules in a solid

Answer 7

Molecules vibrate

Question 8

describe the movement of molecules in a gas

Answer 8

Molecules move freely, randomly, high speed, zig zag

Question 9

explain in terms of momentum how the molecules exert a pressure on the walls of the box

Answer 9

Molecules collide with walls
molecules change momentum
Force = change in momentum/time

Question 10

what is meant by thermometer range

Answer 10

Difference between maximum and minimum temps it can measure

Question 11

what is meant by thermometer sensitivity

Answer 11

Distance moved by liquid thread per degrees Celsius

Question 12

how to calculate tension

Answer 12

Mass x gravity

Question 13

mass equation

Answer 13

Mass = volume x density

Question 14

the two types of waves

Answer 14

Transverse or longitudinal

Question 15

what is a Transverse wave

Answer 15

a wave in which the medium vibrates at right angles to the direction of its propagation

Question 16

what is a longitudinal wave

Answer 16

a wave vibrating in the direction of propagation

Question 17

Image in a plane mirror

Answer 17

Same size
Upright
virtual image

Question 18

What is refraction

Answer 18

When the waves go from one medium to another

eg. A ruler in a water tank

Question 19

Acceleration equation

Answer 19

acceleration = velocity/time

A = vel/time

Question 20

centripetal

Answer 20

Towards the surface

Question 21

3 types of acceleration

Answer 21

positive
negative
Centripetal

Question 22

what is refraction

Answer 22

The bending of light, sound, water and waves. As it passes from one transparent substance into another.

Question 23

What does refraction make possible

Answer 23

Lenses, magnifying glasses, prisms and rainbows.

without refraction, we wouldn’t be able to focus light on our retina

Question 24

critical angle abréviation

Answer 24

c

Question 25

Total internal reflection

Answer 25

More dense -> less dense | angle of incidence > critical angle

Question 26

what happens when white light enters a prism

Answer 26

It splits into a rainbow

Question 27

what is another name for a focal point

Answer 27

Principal focus

Question 28

the centre of the lens is called

Answer 28

optical centre `

Question 29

The line though the centre of the lens and perpendicular to the lens is called

Answer 29

The principal axis

Question 30

equation for the magnifications produced by the lens:

Answer 30

M = image height/object height

Question 31

When does light change direction?

Answer 31

when it enters a lens

Question 32

What temperature does ice melt at

Answer 32

0 degrees celsius

Question 33

What is Lf

Answer 33

specific latent heat of fusion

Question 34

What is Lv

Answer 34

Specific latent heat of vaporisation

Question 35

Equation for energy required to change substance property

Answer 35

``` Energy = mass x latent heat H = m L ```

Question 36

What wave has the highest frequency out of these three: Ultraviolet, radio waves, infrared waves

Answer 36

Ultraviolet has a higher frequency than radio waves and infrared waves

Question 37

What wave has the longest wavelength out of these three: microwaves, xrays, gamma rays

Answer 37

Microwaves have a longer wavelength than X-rays and gamma rays

Question 38

What type of wave is used in satellite communication

Answer 38

Microwaves are used in satellite communication

Question 39

properties of electromagnetic waves:

Answer 39

Transverse waves do not need a medium (can travel through a vacuum) All electromagnetic waves travel with the same high speed of c=3.0x10 to the power of 8 in a vacuum and approximately the same speed in air

Question 40

As wavelength decreases, frequency must ____

Answer 40

increase

Question 41

The higher the frequency of an EM wave the greater its ______

Answer 41

energy

Question 42

Wave equation

Answer 42

Velocity = frequency x wavelength

Question 43

What type of wave is sound

Answer 43

longitudal

Question 44

is measuring the size of earthquakes a use of ultrasound

Answer 44

no

Question 45

Which seismic waves are transverse waves

Answer 45

S-waves

Question 46

Specific heat capacity

Answer 46

The amount of energy required to raise the temperature of 1kg of a substance by 1 degrees celsius

Question 47

How many joules are in a mega joule

Answer 47

1000000 | 1 million

Question 48

Change in thermal energy =

Answer 48

mass x specific heat capacity x temperature change ΔE = mc ΔT

Question 49

Heat capacity for water, ice, steam, aluminium, iron, glass, copper, mercury, gold (J/kg)

Answer 49

``` Water = 4186 Ice = 2090 Steam = 2010 Aluminium = 900 iron = 448 Glass = 837 Copper = 387 Mercury = 138 Gold = 129 ```