Physics 5054/32 — October/November 2023

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

questions

marks

minutes

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

Q110MObservations and MeasurementsExperimental ContextsAnalysis, Conclusions and EvaluationUse of Techniques, Apparatus and MaterialsFree sample

In this experiment you will measure the spring constant $k$ of a spring using two different methods.

The spring constant $k$ of a spring is a measure of the stiffness of the spring. The larger the spring constant $k$ , the more difficult the spring is to stretch.

You are provided with:

a spring
a boss, clamp and stand
a 30 cm ruler
a stop-watch
a 300 g mass.

(a)

Method 1

(i)

Measure the unstretched length $l_0$ of the spring to the nearest 0.1 cm.

Do not include the loops at the end of the spring in your measurement.

$l_0$ = ______ $\text{cm}$

(ii)

Attach the spring to the clamp and suspend the 300 g mass from the spring, as shown in Fig. 1.1.

Fig. 1.1

Measure and record the new length $l_1$ of the spring.

Calculate the extension $e$ of the spring produced by the mass.

Use the equation:

e = l_1 - l_0

$l_1$ = ______ $\text{cm}$
$e$ = ______ $\text{cm}$

(iii)

Calculate the spring constant $k_1$ of the spring.

Use the equation:

k_1 = \frac{300}{e}

$k_1$ = ______ $\text{N/m}$

(iv)

It is important to avoid line-of-sight (parallax) errors when determining the extension of the spring.

Describe how you avoid parallax errors.

______

(b)

Method 2

Pull the 300 g mass down a small distance (about 2 cm) and release it.
Observe that the mass oscillates up and down.
Stop the mass oscillating.
Pull the 300 g mass down a small distance again and release it.

(i)

Measure the time $t_1$ taken for 20 oscillations. Record this time in Table 1.1.

Repeat the measurement. Record this time in Table 1.1 as $t_2$ .

Table 1.1

mass $m / \text{g}$	time $t_1$ for 20 oscillations / $\text{s}$	time $t_2$ for 20 oscillations / $\text{s}$	mean time $t$ for 20 oscillations / $\text{s}$	mean period $T / \text{s}$	$T^2 / \text{s}^2$
300

(ii)

Calculate the mean time $t$ for 20 oscillations and record your answer in Table 1.1.

(iii)

The mean period $T$ of the oscillation is the mean time taken for one oscillation.

Calculate the mean period $T$ .

Calculate the value of $T^2$ .

Record all your values in Table 1.1.

(iv)

Use your value of $T^2$ from Table 1.1 to calculate the spring constant $k_2$ of the spring.

Use the equation:

k_2 = \frac{11.8}{T^2}

$k_2$ = ______ $\text{N/m}$

(c)

Explain why the value for the mean period $T$ obtained by measuring 20 oscillations twice is more accurate than the value obtained by measuring 1 oscillation twice.

______

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3 more questions

Q2Observations and Measurements · Experimental Contexts · Analysis, Conclusions and Evaluation · Use of Techniques, Apparatus and Materials · Planning Experiments and Investigations10M
Q3Observations and Measurements · Experimental Contexts · Analysis, Conclusions and Evaluation · Use of Techniques, Apparatus and Materials14M
Q4Planning Experiments and Investigations · Observations and Measurements · Analysis, Conclusions and Evaluation6M

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