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4 marksHeat Transfer

CAPE Physics Unit 1 · May/June 2025 · Paper 2 · Question 3(d)

Assuming a human has 0.03 m thickness of body fat and skin with a total surface area of 1.7 m², calculate the heat reaching the skin in half-hour if the body temperature is 37 °C and skin surface temperature is 34 °C (thermal conductivity of body fat = 0.20 J s⁻¹ m⁻¹ °C⁻¹).

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Other parts of this question

  1. 3(a)Complete Table 3 to state the thermometric property and ONE use for both a mercury-in-glass thermometer and a constant-volume gas thermometer.[4 marks]
  2. 3(b)Distinguish between heat transfer by conduction and heat transfer by convection.[2 marks]
  3. 3(c)(i)Define specific heat capacity.[2 marks]
  4. 3(c)(ii)Define specific latent heat of fusion.[2 marks]
  5. 3(e)(i)Calculate the heat gained by the ice from the punch in warming up to the melting point.[2 marks]
  6. 3(e)(ii)Calculate the heat gained by the ice in changing phase from a solid to a liquid.[2 marks]
  7. 3(f)(i)Write an expression for the heat gained by the melted ice in warming up to the final temperature, T.[1 mark]
  8. 3(f)(ii)Write an expression for the total amount of heat lost by the punch.[1 mark]
  9. 3(f)(iii)Hence, determine the final temperature, T, of the mixture.[3 marks]
  10. 3(g)(i)Plot a graph of saturated vapour pressure, P, versus temperature, T, on the grid provided in Figure 3, and draw a smooth curve through the points.[4 marks]
  11. 3(g)(ii)Use the curve in (g)(i) to determine the relative humidity on a day when the temperature is 32 °C and the saturated vapour pressure of water in the air is 2.0…[3 marks]

More practice: the rest of this paper · more Heat Transfer questions · all CAPE Physics Unit 1 past papers