Topic 3 Conservation of Energy Flashcards
Q – What is the equation for Gravitational Potential Energy?
A – GPE = mass x gravity x height
Q – What is equation for Kinetic Energy?
A – Kinetic Energy = ½ x mass x velocity2
Q – What is the equation for Efficiency?
A – Efficiency = useful output energy / total input energy
Q – A question states that the Kinetic energy of a car is
900 MJ. What number should we put into our calculator?
A – M = Mega = x106 so we should put
900x106 J
Q – Explain what is mean by ‘conservation of energy’
A – Energy can’t be created or destroyed. It is simply converted from one type to another.
Q – Describe the INPUT, USEFUL and WASTED energy when a kettle boils some water.
A – INPUT = Electrical USEFUL= Heat
WASTED = sound.
Q – How can we lower the amount of wasted heat in a machine with moving parts?
A – lubricate to reduce the amount of friction.
Q – Name 3 ways we can insulate our homes.
A – loft insulation / cavity wall insulation / double glazed windows / carpets / curtains / draught excluders.
Q – Give 3 examples of Non-renewable energy resources
A – Coal / Oil / Gas / Nuclear
Q – Give 2 advantages of renewable energy resources?
A – 1. Won’t run out
- Produce less greenhouse gases
- Much cheaper electricity once built.
Q – Give some examples of Renewable energy resources
A – Sun / Tidal power / Wind power / Hydro-electric power
Q – What is the main difference between renewable and non-renewable energy resources?
A – Non-renewable energy resources will run out.
Q – Will an insulator have a higher or lower thermal conductivity value?
A – a lower value. We don’t want it to conduct heat away.
