DP Physics (last assessment 2024)

Question 20N.2.SL.TZ0.3c

Date	November 2020	Marks available	[Maximum mark: 2]	Reference code	20N.2.SL.TZ0.3c
Level	SL	Paper	2	Time zone	TZ0
Command term	Calculate	Question number	c	Adapted from	N/A

[Maximum mark: 2]

20N.2.SL.TZ0.3c

A sample of vegetable oil, initially in the liquid state, is placed in a freezer that transfers thermal energy from the sample at a constant rate. The graph shows how temperature $T$ of the sample varies with time $t$ .

The following data are available.

Mass of the sample $= 0.32 kg$
Specific latent heat of fusion of the oil $= 130 kJ {kg}^{- 1}$
Rate of thermal energy transfer $= 15 W$

(c)

Calculate the mass of the oil that remains unfrozen after $60$ minutes.

[2]

Markscheme

mass of frozen oil $« = \frac{27 \times 10^{3}}{130 \times 10^{3}} » = 0.21 « kg »$ ✓

unfrozen mass $« = 0.32 - 0.21 » = 0.11 « kg »$ ✓

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Core

Core » Topic 3: Thermal physics » 3.1 – Thermal concepts

Core » Topic 3: Thermal physics

Question 20N.2.SL.TZ0.3c

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