IB Physics HL B 1 9 Specific Heat and Latent Heat Questions

Practise HL thermal calculations for phase changes, experiments, energy losses, flow systems and uncertainty in exam contexts.

Exam points

Apply Q = mcΔT to calculate energy for a temperature change with consistent units.
Apply Q = mL to calculate latent energy for a phase change and distinguish specific heat capacity from specific latent heat using complete evidence.

[Maximum number: 2]

The graph shows the variation with time of the height of the International Space Station (ISS) during a 30-day period.

Figure for Question IB Physics HL B 1 9 Specific Heat and Latent Heat Questions question 1 — IB Physics HL

The following data are available:

\begin{aligned} \text { Mass of Earth } & =5.98 \times 10^{24} \mathrm{~kg} \\ \text { Mass of the ISS } & =4.20 \times 10^{5} \mathrm{~kg} \\ \text { Radius of the Earth } & =6.38 \times 10^{6} \mathrm{~m} \end{aligned}

For the 30-day period indicated in the graph the loss of total energy of the ISS is $4.5 \times 10^{9} \mathrm{~J}$ .

Estimate the increase in the temperature of the ISS assuming all the lost energy went into thermal energy of the ISS. Take the specific heat capacity of the ISS to be $500 \mathrm{Jkg}^{-1} \mathrm{~K}^{-1}$ .

$\begin{aligned} \Delta T=\frac{Q}{m c} \quad \Delta T=\text { « } \frac{4.5 \times 10^{9}}{4.2 \times 10^{5} \times 500}=\gg 21 \mathrm{~K} \text { OR } 21^{\circ} \mathrm{C} \quad \end{aligned}$

Award [2] if 21 is seen as the answer without working

All question bank results loaded

IB Physics HL B 1 9 Specific Heat and Latent Heat Questions question 1