Physics, Autumn 2022 Flashcards
What is the equation for weight?
mass x gravitational field strength
The equation for work done
force x distance
The equation for distance travelled
speed x time
The equation for force on a spring
spring constant x extension
The equation for kinetic energy
0.5 x mass x (speed x speed)
The equation for gravitational potential energy
mass x gravitational field strength x height
The equation for efficiency
useful output power ÷ total input power
Equation for charge
current x time
The equation for density
Mass ÷ time
The equation for electrical power
current x p.d
The equation for potential difference
current x resistance
The equation for weight
mass x gravitational field strength
Equation for power
energy ÷ time
Unit for velocity
m/s
Unit for mass
kilograms (kg)
Unit for energy
Joules (J)
Unit for power
Watts (W)
Renewable is…
…a natural resource or source of energy that is not depleted by use
Examples of chemical energy
In food, fuel and electric batteries
Examples of kinetic energy
in moving objects
Examples of gravitational potential
in objects raised above a planet’s surface
Examples of elastic potential
in stretched, compressed or twisted objects
Examples of thermal energy
in any heated objects
What are the energy stores?
gravitational potential, kinetic, electrostatic, chemical, elastic, nuclear, thermal and magnetic
What is specific heat capacity?
the amount of energy required to raise the temperature of 1kg of a substance by one degree Celsius
What is current?
rate of flow of charge
What happens during static electricity?
Electrons move so one object becomes positive and the other becomes negative.
What is potential difference?
Energy transferred per unit of charge
What is resistance?
measure of how difficult it is for current to flow
In a series circuit, what happens to the current and p.d?
Current is the same everywhere and potential difference is shared between components
In a parallel circuit, what happens to the current and p.d?
Current splits between branches and potential difference is the same for each branch
What does melting do?
When a solid is heated, it absorbs energy, and it melts into a liquid.
What does boiling do?
If the liquid is heated, it absorbs more energy and it boils into a gas.
What does evaporating do?
A liquid turns into a gas slowly, at temperatures that are below its boiling point.
What does condensing do?
If a gas is cooled, it transfers energy to the surroundings, and turns into a liquid.
What does freezing do?
If the liquid is cooled, it transfers energy to the surroundings, and turns into a solid.
Which state changes are exothermic?
Evaporating, condensing and freezing
Which state changes are endothermic?
Boiling and melting.
What causes pressure in gases?
Pressure in gases is caused by particles colliding with the walls of the container.
What increases gas pressure?
Temperature increases or decreases in volume
What is nuclear fission?
The splitting of a larger nucleus into two or more smaller nuclei and two or three neutrons moving at high speeds. Energy is released in the form of gamma radiation.
What is a chain reaction?
If each of the neutrons produced hits a fissionable atom, the rate of fission events rapidly increases. This creates high temperatures and pressures.
What is nuclear fusion?
The joining of 2 smaller atomic nuclei to form a larger one.
Where does nuclear fusion happen?
In stars
Does nuclear fusion create radioactive waste?
No
What fuels nuclear fusion?
Hydrogen
What does nuclear fusion create?
Helium
