1. Tristan - Year 9 Flashcards
What is Hooke’s law?
Used to determine the force to stretch a spring.
Force = Spring constant x extension
What is the equation for elastic potential energy?
Ee = 1/2 x k x e2
Elastic potential energy (j) = 1/2 x spring constant (N/m) x extension2 (m)
What is the equation for kinetic energy?
E<sub>k</sub> = 1/2 x m x v<sup>2</sup> Kinetic energy (j) = 1/2 x mass (kg) x speed<sup>2</sup> (m/s)
What is the equation for change in objects gravitational potential energy store?
Change in objects gravitational energy store (j) = weight (N) x change in height (m)
What is the equation for work done?
W = F x S Work done (j) = force applied (N) x distance moved (m)
What is the conservation of energy?
Energy can not be created or destroyed.
What are thermal energy stores?
The energy a substance has because of its temperature.
What is elastic potential energy?
The energy stored in a springy object when you stretch it or squash it.
What are gravitational potential energy stores?
Used to describe the energy stored in an object because of its position such as an object above the ground.
What are kinetic energy stores?
The energy an object has because it is moving.
What are chemical energy stores.
Fuels, foods or the chemicals found in batteries. The energy is transferred during chemical reactions.
What energy transfer is occurring when an army charges?
Chemical energy to kinetic energy
What energy transfer is occurring when a car drives?
Chemical energy to kinetic energy
Thermal energy stores
Energy a substance has because of its temperature.
Elastic potential energy
Energy stored in an springy object when you stretch it or squash it.
Gravitational potential energy
Energy stored in an object because of its position eg. an object in the air abound the ground.
Kinetic energy stores
Energy an object has due to it moving.
What are chemical energy stores?
Includes fuels, food or chemicals found in batteries. Energy is transferred during chemical reactions.
What happens to the pressure as you increase the volume of a container?
The pressure decreases as there is more space in between the particles and the walls so collisions are less frequent
Which direction does pressure expanding act on the walls of the container?
At right angles
Which condition ensures that temperature doesn’t rise with pressure when the piston is pushed down?
If the compression is slow
What must the force of the piston overcome in order to compress the gas?
The pressure of the gas
What are the units for pressure?
kPa
What’s the formula for calculating the constant of Boyles law?
Constant = pressure x volume
What’s Boyles law?
A law stating that the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature
Explain how heat is transferred via conduction
When the particles are heated they gain energy and vibrate faster, colliding with other particles more transferring heat energy
What is meant by a conductor?
A substance that allows heat energy to transfer through it easily
Describe what is meant by an insulator
A substance that does not allow heat energy to travel through it easily
Give an example of a conductor
Metal
Give an example of an insulator
Wood or plastic
Which of the following has the highest thermal conductivity? Wood or metal
Metal
What is the meaning of thermal conductivity?
How well a substance transfers heat through it
Heat from radiation is emitted in…
Waves
Heat given off from the body is an example of which energy transfer?
Radiation
The water in a kettle boiling is an example of which energy transfer?
Convection
A saucepan getting hot is an example of what kind of energy transfer?
Conduction
Where do more dense particles go?
To the bottom
Which type of energy transfer takes place in a vacuum?
Radiation
What happens to fluid particles as they are heated?
They gain energy and expand, becoming less dense and rise to the top
Which state of matter is not a fluid?
Solid
What type of heat transfer happens in fluids?
Convection
What type of heat transfer happens in solids?
Conduction
Why does increasing the temperature of a sealed gas container increase the pressure?
The energy transferred to the gas increases the kinetic energy and the speed increases, causing the particles to hit the walls of the container with greater force and more often
What’s the control variable?
Things we keep the same
What’s he dependent variable?
The thing that you’re measuring
What’s the independent variable?
The thing that you change
What’s the formula for pressure?
Pressure = force / area
How do you measure the volume of a liquid?
Using a measuring cylinder
How do you measure the mass of a liquid?
Place the liquid in a measuring cylinder and onto a balance
How do you measure the volume of an irregular object?
Fill an eureka can up to the sprout with water, place object inside so that it displaces water
How do you measure the mass of an irregular object?
Balance
How do you measure the volume of a regular object?
Measure the height, length and width using a ruler and multiply together to find the volume
Explain why the pressure on the container walls increases as the temperature rises?
The particles have more kinetic energy, hit the walls more frequently and with more force as they travel at higher speeds,
How do you measure the mass of a regular object?
Using a balance
What is pressure?
Force per unit area
What is meant by gas pressure?
The force that a gas exerts on the walls of it’s container
What are the units for density?
Kg/m^3
What’s the formula for density?
Density = mass/volume
What’s the arrangement of dense substances?
Particles are densely packed with little air spaces in between
What’s density?
A measure of the mass per unit of volume of a substance
What are the units for specific latent heat?
J/kg
What’s the formula for specific latent heat?
E=mL
What’s specific latent heat of vaporisation?
The energy required to change 1kg of a substance from a liquid to a gas without changing the temperature
What’s specific latent heat of fusion?
The energy required to change 1kg of a substance from solid to liquid without changing the temperature
What’s specific latent heat?
The amount of energy required change state of one kilogram of a substance with no change in temperature
What’s latent heat?
The energy needed for a substance to change state
Why is energy needed to change state?
To overcome the intermolecular forces between the particles
What are formed when a change of state occurs due to cooling?
Intermolecular forces
Which energy type is added or removed during a change in state?
Thermal energy
Why is it important to say we still have the same substance but in a different form when there’s a change of state?
If you reverse the change, the substance with return to its original form and properties and the number of particles don’t change but they’re just arranged differently as mass is conserved
What does kinetic theory of particles explain?
The properties of the different states of matter; solids, liquids and gases. each with different amounts of energy, arranged differently and move differently
Are changes of state physical or chemical changes?
Physical because no new bonds are made
What’s the difference between evaporation and boiling?
Evaporation happens on the surface to the particles with the most energy whereas boiling happens throughout the liquid and all particles have high enough energy to break bonds
How does temperature link to the movement of particles and their kinetic energy?
The movement of particles increases alongside temperature as the particles gain kinetic energy
What are the characteristics of the state of gas?
Particles move at high speeds, random directions, move freely, spaced far apart, random arrangement, compressed and can fill the shape of any container
Which change of state describes gas to solid?
Deposition
What are the characteristics of the state of solid?
Regular arrangement, tightly packed particles, vibrate about a fixed point, fixed shape and cannot flow nor be compressed
What are the characteristics of the state of liquid?
Close together, random arrangement, move freely, take the shape of the container and they cannot be compressed
Which change of state describes solid to gas?
Sublimation
How does a hydroelectric dam work?
Water passes down the channel and turns the turbine.
The turbine spins the generator.
The generator converts this movement into energy.
How does a power plant work?
Fuel is burned.
The water tank is heated from the steam.
The steam passes through a turbine and the turbine spins.
The turbine causes the generator to spin making electricity.
What is wave power?
A wave generator uses the motion of the waves to turn a generator and make electricity.
How does a turbine make electricity?
The kinetic energy is transferred into electricity.
What are the different types of solar energy?
Water heating solar panels, electricity-generating solar cells, solar tower power plants,
What are the different types of solar energy?
Water heating solar panels, electricity-generating solar cells, solar tower power plants,
What are the advantages of nuclear power?
- No greenhouse gases
It has a very high energy density - this means we extract far more energy per kg of fuel compared to other energy sources.
What are the disadvantages of nuclear power?
Risk of nuclear accidents
Used nuclear fuel is highly radioactive and needs to be stored away from humans for centuries.
