Physics 5054/31 — May/June 2012

Cambridge O-Level · Practical Test · worked solutions for every part, with the mark scheme

questions

marks

120

minutes

Topics Observations and Measurements · Experimental Contexts · Analysis, Conclusions and Evaluation · Use of Techniques, Apparatus and Materials · Planning Experiments and Investigations

Q15MObservations and MeasurementsExperimental ContextsUse of Techniques, Apparatus and MaterialsAnalysis, Conclusions and EvaluationFree sample

In this experiment, you will determine the mass of a piece of modelling clay.

You have been provided with

a piece of modelling clay,
a metre rule,
a knife-edge,
a 50 g mass.

(a)

Balance the metre rule on the knife-edge. The knife-edge shows the position of the centre of mass of the rule. Record the position of the knife-edge.

position of knife-edge = ______

(b)

Place the modelling clay at one end of the metre rule and adjust the position of the $50\text{ g}$ mass at the other end until the rule balances. The knife-edge must remain below the centre of mass of the rule. The arrangement is shown in Fig. 1.1.

Fig. 1.1

(i)

Determine the horizontal distance $x$ from the centre of the modelling clay to the knife-edge and the horizontal distance $y$ from the knife-edge to the centre of the $50\text{ g}$ mass.

$x$ = ______
$y$ = ______

(ii)

Explain how you ensured that your measurement of $y$ was taken to the centre of the $50\text{ g}$ mass.

(iii)

Calculate the mass $M$ of the modelling clay using the relationship

M = \frac{50y}{x}\text{ gram}.

$M$ = ______

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3 more questions

Q2Observations and Measurements · Experimental Contexts · Analysis, Conclusions and Evaluation5M
Q3Observations and Measurements · Experimental Contexts · Analysis, Conclusions and Evaluation5M
Q4Experimental Contexts · Observations and Measurements · Analysis, Conclusions and Evaluation · Planning Experiments and Investigations15M

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