Physics

Question 1

Control Variable

Answer 1

The variable that is kept constant throughout the experiment to ensure a fair test. For example, in testing plant growth with different light sources, the water, soil type, and temperature should be constant.

Question 2

Independent Variable

Answer 2

The variable that you intentionally change to observe its effect. Whilst testing plant growth example, this would be the type of light.

Question 3

Dependent Variable

Answer 3

The variable you measure as the result of the change. Whilst testing plant growth, it would be the height or growth rate of the plant.

Question 4

Discrete Data

Answer 4

Data that can only take certain values, often whole numbers (e.g., number of petals on a flower).

Question 5

Categoric Data

Answer 5

Data that falls into distinct groups or categories (e.g., eye colour, type of metal).

Question 6

Continuous Data

Answer 6

Data that can take any value within a range (e.g., temperature, mass, time).

Question 7

Thermal Energy stores

Answer 7

Energy stored in an object due to its temperature (e.g., hot tea). Kinetic: Energy of a moving object (e.g., a speeding car).

Question 8

Gravitational potential

Answer 8

Energy stored in an object at height (e.g., a rock on a cliff).

Question 9

Elastic Potential store

Answer 9

Stored in stretched or compressed objects (e.g., a stretched rubber band).

Question 10

Chemical energy store

Answer 10

Stored in fuel, food, batteries (e.g., gasoline).

Question 11

Magnetic energy store

Answer 11

Stored when magnetic poles are pushed together or apart (e.g., bar magnets).

Question 12

Electrostatic energy store

Answer 12

Stored when opposite charges are separated (e.g., static electricity on a balloon).

Question 13

Nuclear

Answer 13

Stored in the nucleus of atoms, released in nuclear reactions.

Question 14

Conservation of Energy

Answer 14

Energy cannot be created or destroyed, only transferred or transformed from one store to another. Total energy in a closed system remains constant.

Question 15

Efficiency

Answer 15

The ratio of useful energy output to total energy input. Formula: Efficiency (%) = (Useful energy output / Total energy input) x 100

Question 16

Power

Answer 16

The rate at which energy is transferred or work is done. Power (W) = Energy transferred (J) / Time (s)

Question 17

Kilowatt-hour (kWh)

Answer 17

A unit of energy used in homes and electricity bills. Energy (kWh) = Power (kW) x Time (hours)

Question 18

Fuels

Answer 18

Materials that store chemical energy and can be combusted to release energy. E.g: Coal, oil, natural gas, petrol, biomass.

Question 19

How a Power Station Works

Answer 19

Fuel is burned to heat water, producing steam. Steam turns turbines connected to a generator. Generator converts kinetic energy into electrical energy. Cooling systems condense steam for reuse.

Question 20

Comparing Energy Sources

Answer 20

Fossil Fuels: Reliable but polluting, finite. Nuclear: Low emissions but radioactive waste. Solar: Renewable but dependent on sunlight. Wind: Clean but variable output. Hydroelectric: Reliable, eco-impact on habitats. Biomass: Renewable but may compete with food crops.

Question 21

Types of Forces

Answer 21

Gravitational: Earth pulling objects down. Friction: Opposes motion, e.g., brakes. Air Resistance: Slows objects in air. Tension: Pulling force in a rope. Normal: Perpendicular support force. Upthrust: Buoyant force in fluids. Magnetic: Between magnetic poles. Electrostatic: Between charged particles.

Question 22

Equilibrium and Balanced Forces

Answer 22

Equilibrium: All forces are balanced; objects at rest or moves at constant speed. Unbalanced: Causes acceleration or change in motion

Question 23

Resultant Force

Answer 23

Net force from combining all acting forces. Change in motion depends on size and direction.

Question 24

Newton’s Second Law

Answer 24

F = MxA. Force = Mass x Acceleration. Determines how a force affects motion.
You can use A = F/M to calculate acceleration.

Question 25

Mass vs. Weight

Answer 25

Mass: Amount of matter (kg),is constant. Weight: Force of gravity on mass (N), can vary depending on the gravity. Formula: Weight = Mass x Gravity

Question 26

"Work Done"

Answer 26

Work = Force x Distance moved in direction of force. Measured in Joules (J)

Question 27

Gravitational Potential Energy formula

Answer 27

GPE = mass x gravity x height

Question 28

Upthrust and Density

Answer 28

Upthrust: Upward force in liquids and gases. Density Formula: Density = Mass / Volume

Question 29

Air Resistance

Answer 29

Caused by collision with air particles. Gets affected by speed, shape, and area impact it.

Question 30

Friction

Answer 30

Requires contact and rough surface. An object rubs on the rough surface creating a large amount of heat.

Question 31

Hooke's Law formula

Answer 31

F = k x x. Force = Spring constant x Extension. Applies within elastic limit. Once elastic limit is reached this no longer applies.

Question 32

Simple vs complex machines

Answer 32

Simple machines such as lever, pulley, inclined plane reduce the amount of energy required. Complex machines are made of simple machines.

Question 33

Things in the Solar System

Answer 33

Sun, 8 planets, moons, asteroids, comets. Planet Order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

Question 34

Why do we have seasons?

Answer 34

The earth is at a tilted axis and has an orbit that is not a perfect circle. This changes the amount of sunlight that the earth gets.

Question 35

Moon Phases

Answer 35

The Moon's appearance changes due to its position relative to Earth and Sun. Reflects sunlight, cycles every ~29.5 days. The moon phases are new Moon, followed by waxing crescent, first quarter, waxing gibbous, full Moon, waning gibbous, third quarter and finally waning crescent.

Question 36

Tides

Answer 36

Due to the Moon's gravity pulling on Earth’s water. Spring Tide: Sun + Moon aligned, highest. Neap Tide: Sun and Moon at right angles, lowest.

Question 36

Charge and Electrons

Answer 36

Charge: Property of matter; electrons negative. Electrons move to create current.

Question 37

Electroscope

Answer 37

An electroscope detects static electricity.

Question 38

Van de Graaff Generator

Answer 38

A belt generates an electric charge and moves it to the big metal ball creating high voltage electricity.

Question 39

Electric Field

Answer 39

A region where there is a charge. If there is a negative charge field it will repel other fields that have a negative charge.

Question 40

Conductors vs Insulators

Answer 40

Conductors transfer a large amount of the heat/electricity and insulators absorb more of the heat/electricity.

Question 41

Current, Voltage, Resistance

Answer 41

Current (I): Flow of charge, A. Voltage (V): Energy per charge, V. Resistance (R): Opposition to flow, Ω.

Question 42

Ohm's Law

Answer 42

V = I x R

Question 43

Series vs Parallel Circuits

Answer 43

A series circuit has a circuit one path making it easily destroyed if it gets broken. A parallel circuit has multiple paths, making it so if one path is broken the other path does not get broken.

Question 44

Magnetic Materials

Answer 44

Iron nickel steel cobalt

Question 45

Magnetic pole reactions

Answer 45

Like poles repel and opposite poles attract

Question 46

Earth's Magnetic Field

Answer 46

Created by the Earth's core and can be used with things such as compasses to navigate us.

Question 47

Temporary Magnets vs permanent magnets

Answer 47

Temporary magnets are created by putting a magnetic material inside a magnetic field and will lose magnetism quickly. Permanent magnets are always there

Question 48

Electromagnets

Answer 48

Can be created by passing electricity through a coil around a pole with the amount of electricity, material of the pole, length of the coil can all change the strength of the electromagnet.

Question 49

Waves

Answer 49

Transverse: Vibrations at right angles (e.g., light) and can travel through solids but not liquid and gases (light is also an electromagnetic wave). Longitudinal: Vibrations parallel (e.g., sound).

Question 50

Light Keywords

Answer 50

Transparent: All light through. Translucent: Some light through. Opaque: No light through. Reflect: Light bounces. Refract: Light bends. Absorb: Light taken in. Luminous: Makes its own light. Non-luminous: Reflects light. Source: Origin of light.

Question 51

Pinhole Camera

Answer 51

A box has light pore into it through a small whole with the light going in a diagonal but straight line causing the object to be viewed us upside down from the seeing area.

Question 52

Reflection

Answer 52

Angle of incidence = angle of reflection. Light can bounce off of certain materials causing reflection.

Question 53

Refraction

Answer 53

Light bends and goes somewhere else due to it changing speed when passing through a new medium.

Question 54

Dispersion

Answer 54

Splitting of light into a spectrum (rainbow) using a prism due to different speeds of colours.

Question 55

Filters

Answer 55

Filters allow only certain colours through

Question 56

Colour Perception

Answer 56

Seen colour = light reflected. Other colours are absorbed by the object. White means no light has been absorbed and black means all of the light has been absorbed.

Question 57

The Eye

Answer 57

Cornea: Bends light. Lens: Focuses light. Iris: Controls light entry. Retina: Detects light. Optic Nerve: Sends signals to the brain which flips the image due to the image being upside down from the same concept as the pinhole camera.

Question 58

How we see colour

Answer 58

The Cones at the back of our eyes detect red, green, blue. Brain processes combinations to perceive the full spectrum however the spectrum is only what we cans see as certain animals can see a lot more or less colours than a human.