Heat Questions - GCSE Level

Q8. The diagram shows an outdoor pizza oven.

(a) A solid biofuel is used to heat the oven. Name one solid biofuel.

Wood, charcoal or peat

[1 mark]

(b) The pizza oven is made of concrete. The mass of the concrete is 250 kg.

Given that concrete has a specific heat capacity of 880 J / kg °C, calculate the temperature increase when 8.36 × 107 J of energy are transferred to the concrete.

Energy supplied = Mass x Specific heat capacity x Temperature rise

8.36 x 107 = 250 x 880 x θ

θ = 8.36 x 107 / (250 x 880)

θ = 380 °C

[2 marks]

(c) The pizza oven is designed to stay hot for at least two hours. Describe how each of the four labelled design features helps to ensure that the pizza oven stays hot for at least two hours.

White is a poor emitter of IR radiation, therefore the heat energy will not escape as easily as if it was painted with a dark colour.

A curved surface has a small surface area to volume ratio. The surface are being minimised means that there is less area for the heat energy to escape from.

The high specific heat capacity of the concrete means that a large amount of energy would be needed to have been transfered to the surroundings before the temperature decreased significantly.

A low U-value means that concrete is a poor conductor of heat (or a good insulator) - preventing easy heat loss from the oven.

[4 marks]

(7 marks total)