Energy Flashcards
What is a system?
A system is an (group of) object.
What are the changes involved when an object is thrown upwards?
The objects kinetic energy is transferred to gravitational potential energy.
What are the changes involved when a moving object hits an obstacle?
The objects kinetic energy is transferred to elastic potential and thermal energy stores of the object, and transferred away by sound waves.
What are the changes involved when an object is accelerated by a constant force?
The work done on the object is transferred to its kinetic energy store.
What are the changes involved when a vehicle is slowing down?
The friction between the brakes, wheels and the ground does work - causes energy transfer from wheels kinetic energy to thermal energy store of the surroundings.
What is power?
The rate at which energy is transferred/work is done.
What is the conservation of energy?
Energy be transferred, stored or dissipated, but cannot be created or destroyed.
How does lubrication reduce unwanted energy transfers?
It reduces the effects of friction on an object, which reduces the loss of kinetic energy.
How does insulation reduce unwanted energy transfers?
It reduces/prevents the loss of thermal energy in an object.
How to increase the efficiency of an intended energy transfer?
Add lubrication/insulation.
What are the 3 main fossil fuels?
Coal, oil and gas.
Name 5 renewable energy resources.
Bio-fuel, Geothermal, Solar, Wind and hydro-electric.
What the 3 main uses of energy resources?
Transport, electricity and heating.
Why are some energy resources more reliable than others?
Some are more reliable because they can never run out e.g. geothermal and because some can’t be accessed at all times e.g. solar.
What is the environmental impact of using fossil fuels?
They release greenhouse gases which contribute to global warming.
