2.3 Transfer of thermal energy

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Question 16

A student investigates the rate of cooling of water in a beaker.

The table below shows the temperature $θ\theta$ of the water recorded at regular intervals of time $t$ :

$\text{ / s}$	$∘C\theta \text{ / } ^\circ\text{C}$
0	88
30	81
60	76
90	72
120	69
150	66
180	63

(i) Calculate the decrease in temperature $Δθ1\Delta \theta_1$ of the hot water between times $0\text{ s}$ and $60\text{ s}$ . (ii) Calculate the average rate of cooling $R_1$ of the water during this interval using the equation:

R_1 = \frac{\Delta \theta_1}{\Delta t}

where $s\Delta t = 60\text{ s}$ . Include the unit.

[3]

(i) Calculate the decrease in temperature $Δθ2\Delta \theta_2$ of the hot water between times $120\text{ s}$ and $180\text{ s}$ . (ii) Calculate the average rate of cooling $R_2$ of the water during this interval using the equation:

R_2 = \frac{\Delta \theta_2}{\Delta t}

where $s\Delta t = 60\text{ s}$ .

[2]

A student suggests that the rate of cooling is higher when the temperature of the water is higher. State and explain whether the results support this suggestion.

[1]

Suggest one suitable addition to the apparatus for an experiment designed to investigate:

Thermal energy loss by evaporation from the surface.
Thermal energy loss by conduction through the sides of the beaker.

[2]

\text{ / s}

∘C\theta \text{ / } ^\circ\text{C}

120

150

180

2.3 Transfer of thermal energy

Question 16

Markscheme

2.3 Transfer of thermal energy

Question 16

Markscheme

2.3 Transfer of thermal energy

Question 16

2.3 Transfer of thermal energy Questions

2.3 Transfer of thermal energy

Question 16

2.3 Transfer of thermal energy Questions