Alternative to Practical: answer from the supplied diagrams and data. Upload drawings or graphs where requested; measurements taken from figures should be shown with their workings.
(a)A test-tube about one-third full of hot water is lowered into a beaker containing 200 cm³ cold water, as in Fig. 2.1 and Fig. 2.2. A thermometer measures its initial temperature after about 30 s. Read Fig. 2.3 and enter the temperature in Table 2.1 at t = 0 s.
[1 mark]
(b)(i)Complete the units in the Table 2.1 headings: time t / , temperature θ / for a test-tube cooling in cold water, and temperature θ / for a test-tube cooling in warm water.
Answer guidance
Complete Fill in every gap. A partly completed answer usually scores partly.
[1 mark]
(b)(ii)Measurements were made every 30 s for a further 180 s. Complete the seven-entry time column of Table 2.1, beginning at t = 0 s.
Answer guidance
Complete Fill in every gap. A partly completed answer usually scores partly.
[1 mark]
(c)For the arrangement in Fig. 2.2, describe in detail one precaution to make the temperature measurements as accurate as possible.
[1 mark]
(d)(i)The student repeats the procedure in warm water using Fig. 2.4. Identify and explain the anomalous warm-water temperature reading in Table 2.1. Its seven readings, at 30 s intervals from t = 0 to 180 s, are 75, 68, 63, 58, 55, 35, 52 °C.
Answer guidance
Identify Name it and, where the marks allow, say what led you there.
[2 marks]
(d)(ii)Calculate the decrease in hot-water temperature after 180 s for both beakers. Table 2.1 leaves the initial cold-water-beaker reading for your answer to 2(a), and prints 34 °C at 180 s; the warm-water-beaker readings are 75 °C initially and 52 °C at 180 s.
Answer guidance
Calculate Show your working. The method can earn marks even when the final value is wrong, and a bare answer often cannot.
[1 mark]
(e)(i)Use your answers to 2(d)(ii) to conclude how the water temperature in the beaker affects the rate of cooling of hot water in the test-tube. Support the conclusion with the measurements.
Answer guidance
Using You must use the thing it names. An answer that reaches the right value another way may not score.
[2 marks]
(e)(ii)Suggest one improvement to the procedures with cold and warm beakers to make comparison between their cooling rates more valid.
Answer guidance
Suggest More than one answer may be acceptable, so long as it is consistent with the physics.
[1 mark]
5054/42/M/J/24Cambridge O Level Physics 5054 · May/June 2024 · Paper 4 variant 2 · Question 2