Unit 1 - Energy Flashcards
What is energy?
Cannot be created or destroyed only transferred. Whenever anything happens energy changes between forms.
How do you calculate kinetic energy? What goes on top of the triangle?
Kinetic energy = 0.5 x mass x velocity^2. Kinetic energy.
What is energy measured in? What is mass measured in? What is the velocity measured in?
Joules (J). Kilograms (kg). Metres per second (m/s).
If a spring is stretched what does it store?
Elastic potential energy.
How can you increase the amount of elastic potential energy stored in a spring?
Increase the extension of the spring or increase the spring constant.
What do the springs store?
Elastic potential energy.
What is gravitational field strength?
The pull of gravity on each kilogram.
What is potential energy?
The energy which is stored in an object because of its position. Either in a spring because its stretched or in an object that’s been lifted.
How do you calculate elastic potential energy? What is on top of the triangle?
Elastic potential energy = 0.5 x spring constant x extension^2. Epe.
What is epe measured in? What is spring constant measure in? what is extension measured in?
Joules (J). Newtons per metre (N/m). Metres (m).
What is spring constant?
How much an object will stretch by. If you need a lot of force it has a higher spring constant, less is lower.
How do you calculate gravitational potential energy? What is on top of the triangle?
Gravitational potential energy = mass x gravitational field strength x height. Gpe.
What is gpe measured in? What is mass measured in? What is gfs measured in? What is height/extension measured in?
Joules (J). Kilograms (kg). Newtons per kilogram (N/kg). Metres(m).
What does a ball have more of if it is dropped from a greater height? As it falls what decreases? What increases? What is GPE transferred to?
Gravitational potential energy. GPE. KE. KE.
What is dissipated energy?
The energy which is wasted - not transferred usefully to surroundings.
What is specific heat capacity? What does the amount of energy needed to change the temperature depend on? Why is water a very useful way of transferring large amounts of thermal energy? Give example. What can water absorb a lot of? Give example.
A measure of how much energy is required to raise the temperature of a 1kg substance by 1*C. Mass, material and temperature change. Water can release a lot of energy without a large temperature decrease. Central heating system. Thermal energy from a hot object so can cool many car engines.
What is power? What is it measured in? What is it equal to?
The rate at which energy is transferred or the rate that work is done. Watts. One joule transferred every second.
How do you calculate power? What is on top of the triangle?
Power = energy transferred/time. Energy transferred.
What is power measured in? What is energy measured in? What is time measured in?
Watts (W). Joules (J). Seconds (s).
What does work done and frictional forces causes?
Energy transfer.
What can be used to reduce friction?
Lubrication - oil.
How can you insulate an object? What will this do?
Wrap thermal insulation around and object to stop it losing heat. Thicker material is better insulation.
What is a thermal image? What is it taken using?
Thermogram. Infared radiation.
What is energy efficient?
When less energy is wasted so the transferred energy is used ruefully. Less dissipated.
How do you calculate efficiency? What is on top of the triangle?
Efficiency = useful output energy / total input energy. Useful output energy.
What is efficiency measured in? What is energy measured in? What is power measured in?
Percentage or decimal. Joules (J). Watts (W).
In the practical with different insulating materials, which should have been the best? Why? Which should lose the most heat?
Bubble wrap because it is the thickest and contains air which is a good insulator. One with no material as it has no insulator.
Which material should help maintain heat? Why? Which shouldn’t maintain heat? Why?
Aluminium foil as it reflects the heat back. Newspaper, as it is dark so, emits the heat.
Name the energy resources.
Solar, wind, coal, oil, gas, nuclear, tidal, wave, hydroelectric, geothermal, biofuel.
Which energy resources are renewable?
Waves, tidal, hydroelectric, geothermal, solar, wind, biofuels.
Which energy resources are non-renewable?
Nuclear, gas, oil, coal.
Which energy resources are reliable?
Tidal, hydroelectric, geothermal, oil, gas, coal, nuclear, biofuels.
Which energy resources are unreliable?
Wind, solar, waves.
