Paper 4 Jun 1999 Physics

Answer guide for O Level Physics (5054/4) – Paper 4 Alternative to Practical June 1999

1(a)

(b)

(c)

2(a) (b) (c)

3(a)(i) (ii) (b)(i) (ii) (c)

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Any three from: Make sure the rule is parallel to the stationary thread Use a second clamp to hold it steady Use a small ruler at right angles to the rule in line with the centre of the bob and the lower point of the clamp or attach a pointer at each position (or show on a diagram) Calculate the difference of the two readings The stopwatch is not sufficiently accurate/ has an uncertainty of 0.1 s / it would have read T = 1.0 s / There is a reaction time in starting and stopping. 20 swings takes longer so the time is more accurately measured / it would read t = 20.6 s so T = 1.03 s 1 : 46 . 6

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0.02 0.4 Y The maximum current is 0.4 (A) / it would be more accurate Remove the thermistor from the oil, the current changes very little or Disconnect the thermistor, the current falls to almost zero

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11.5 / 14.5 = 0.79 or 0.8 1/5 or 0.2 The ball would not bounce All of its energy is transferred to the glass Volume / mass

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© UCLES 2002

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Answer guide for O Level Physics (5054/4) – Paper 4 Alternative to Practical June 1999

4(a)(i)

FA = 4.5 (units not essential) FB = 1.9

(ii)

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θA / B = 2 FA / FB = 2.37

(iii)

(b) (c)

5(a)

(b)

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The rate of cooling is greater at greater excess temperature The excess temperature and rate of cooling are proportional / When the excess temperature doubles the rate of cooling increases by 2.37 times 1 All points lie on a smooth curve / short period of time 1 To avoid draughts 1

Correct y-axis and sensible scale Correct x-axis and sensible scale Accurate plotting (5 points) (4 points) (1) Best straight line, neat, thin and with good judgement One of : Have the rule close to the lens and screen Use a set square to line up the lens / screen with the rule or similar

© UCLES 2002

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