Questions Corrections 2019

Question 1

Light bulbs should also be labelled with the rate at which they emit visible light. Suggest why

Answer 1

Bulbs also transfer thermal energy
So the efficiency of the light bulb also needs to be considered

Question 2

When electric cars are not being driven, energy stored in their batteries could be used to meet sudden peaks in electricity demand, Suggest how

Answer 2

When cars are plugged in
The energy from car batteries could be transferred back to the national grid

Question 3

As the person moves down the zip wire her increase in kinetic energy is less than her decrease in gravitational potential energy
Explain why

Answer 3

Work done against air resistance
Causin gthermal energy to be transferred to the surroundings

Question 4

Explain why different people have different speeds at the end of the zip wire

Answer 4

Different people have different surface areas
So would be affected by air resistance differently

Question 5

Explain how the internal energy of water changes as it is heated from 20 to 25 Celsius

Answer 5

Kinetic energy of the particles increases
Which increases energy of the water