In which section of the graph is the water boiling?
[1 mark]
.2
Explain why the temperature does not change in section B, even though energy is still being transferred to the ice.
[2 marks]
.3
The mass of the ice is 0.50 kg. The specific latent heat of fusion of ice is 334 000 J/kg.
Calculate the energy needed to melt all of the ice.
[2 marks]
6 marksFoundation and Higher6.1.1.4 Power6.1.1.2 Changes in energy
AQA Trilogy 8464
Spec and skills
Paper scope: P1
Spec 6.1.1.4
Spec 6.1.1.2
Original practice question
Answer and supported method checks
An electric motor in a lift raises the lift through a height of 12 m in 20 s. The mass of the lift is 800 kg.
Gravitational field strength = 9.8 N/kg.
.1
Calculate the energy transferred to the lift's gravitational potential store.
[2 marks]
.2
Calculate the useful power output of the motor.
[2 marks]
.3
A second motor raises the same lift through the same height in 30 s.
Explain why the second motor has a lower power output.
[2 marks]
6 marksFoundation and Higher6.1.3 National and global energy resources
AQA Trilogy 8464
Spec and skills
Paper scope: P1
Spec 6.1.3
Original practice question
Answer and supported method checks
A country needs a new power station. It could build a hydroelectric power station in a mountain valley or a gas-fired power station near a town.
Comparison of two power stations. Hydroelectric: fuel cost none; carbon dioxide when generating none; start-up time about 1 minute; building cost very high; needs a flooded valley. Gas-fired: fuel cost high; carbon dioxide when generating yes; start-up time about 15 minutes; building cost medium; can be built near towns.
Feature
Hydroelectric
Gas-fired
Fuel cost
None
High
Carbon dioxide when generating
None
Yes
Start-up time
About 1 minute
About 15 minutes
Building cost
Very high
Medium
Site
Needs a flooded valley
Can be built near towns
Evaluate the two options. Use information from the table and your own knowledge.
