Mechanical
Heat Transfer
Electricity
Calculations
More calculations
100
The type of energy an object would have at the top of a hill.
Gravitational potential energy
100
Three ways that heat can be transferred.
Conduction, convection and radiation.
100
A measure of how many electrons are moving in a circuit.
Current
100
The resistance of a bulb is 2.5 ohms and the voltage across the bulb is 6 volts. What is the current flowing through the bulb?
2.4 Amps
100
Calculate the heat energy absorbed by 150g of liquid water to raise its temperature by 20॰C.
1(cwater) = 4200 Jkg-1॰C-1)
12,600J
200
The energy change occurring as a rock rolls down a hill.
Gravitational potential energy to kinetic energy
200
What is conduction?
Transfer of heat energy between particles in a solid.
200
Name the two main types of circuits.
Series and parallel
200
An electric heater is rated at 700W. If the heater is connected to a 240V power supply, calculate the current that must flow through the heater.
2.92 A
200
Calculate the work that must be done to lift a 3 kg object up 8m.
240J
300
The definition for work.
A measure of how much energy has been transferred or transformed.
300
What is convection?
The transfer of energy between particles in a liquid or gas.
300
What happens to the current in a parallel circuit?
The current is split between the different pathways in a parallel circuit.
300
How much gravitational potential energy does a 3 kg rock have at the top of a 55m cliff?
1650J
300
A bucket filled with 1.5kg of water at 42॰C is placed in the freezer until it reaches 0॰C. Calculate how much energy has been removed from the water? Specific heat capacity of water is 4200 Jkg-1॰C-1
264,600J
400
The definition of power.
How quickly energy can be transformed or transferred.
400
What is radiation?
The transfer of energy via waves of electromagnetic radiation.
400
What happens to the voltage in a series circuit?
The voltage is shared between the components in a series circuit.
400
How much kinetic energy does a 2000kg car have when it is travelling at 12.3 m/s?
151,290J
400
A car with a mass of 1150 kg accelerates from rest to reach a speed of 24 ms-1. If the car took 11 seconds to accelerate to 24 ms-1, what was the power output of the engine?
30,109 W
500
Why does Ek not usually equal Ep in the real world?
Because of friction which causes some of the energy to be transformed into other forms such are heat, sound etc.
500
What is latent heat?
The energy (thermal) required to turn a solid to a liquid.
500
Explain which bulb will be the brightest.
The top one. P = VI and it has the most voltage across it, and the most current through it.
1) Because it has the same voltage as the power supply, and the voltage for each other bulb is half that.
2) It will have twice as much current flowing through it compared to the other bulbs.
500
An electric heater is rated at 700W. How much energy is required to run the heater for 5 hours?
12,600,000J
500
Calculate the heat energy required to heat 3.0 kg of ice at -9.0॰C to become liquid water at 30॰C. (c ice = 2100 Jkg-1॰C-1 L fusion(ice) = 334000 Jkg-1 c(H2O(l)) = 4200 Jkg-1॰C-1)
Note: - this question requires 3 calculations.
1,436,700J