1. Energy Flashcards
1. List the 8 energy stores?
1.Thermal, Kinetic, Gravitational Potential, Elastic potential, Chemical, Magnetic, Electrostatic, Nuclear
- What are the pathways that energy can be transferred by?
- Heating, Work done by an electric current, work done by a force
- What are the units for velocity?
- m/s
- What are the units for mass?
- kg (kilograms)
- What are the units for energy?
- J (Joules)
- When will an object have no energy in its kinetic energy store?
- When it is not moving
- When is energy transferred to the gravitational potential energy store?
- When an object is lifted up (through a gravitational field)
- What is the value for gravity on Earth?
- 9.8 (unless they tell you to use a different number for gravity!)
- What is the unit for height?
- m (metres)
10.When is energy transferred to the elastic potential store?
- When an object is stretched or squashed
12.What is specific heat capacity?
- Then energy needed to increase the temperature of 1kg of a material by 1⁰C
13.Specific heat capacity of oil is 2100 J/kg/⁰C. How much energy is needed to raise the temperature of 1kg of oil by 1⁰C?
- 2100J
14.What is power? What is the unit for Power?
- Rate of energy transfer, Watts (W)
15.What are the units for work done?
- Joules (J) – work done = energy transferred
16.Why is a system not 100% efficient?
- Some energy is always wasted
17.In a light bulb, 25J of energy is supplied. 5J are usefully transferred into light energy. What is the efficiency of the bulb?
- 5/25 = 0.2 x100 = 20%
18.What happens to waste energy?
- Dissipated as heat (spreads out and becomes less useful)
19.Give three examples of insulation that can be used in the house.
- Cavity wall insulation, loft insulation, double glazing
20.What different ways we can get energy (energy resources)?
- Coal, oil, gas, nuclear, wind, hydro-electricity, solar, bio-fuel, tides, geothermal
21.What is a renewable resource?
- One that won’t run out - we can replace as fast as we use it.
22.What is finite resource?
- One that will run out (non-renewable)
23.Name 3 fossil fuels.
- Coal, oil, gas
24.What are the advantages and disadvantages of a nuclear power station?
- Adv - cheap source of energy, get a lot of energy, reliable
Disadv - finite, nuclear waste is dangerous, expensive to decommission