Physics 9702/21 — October/November 2021

Cambridge AS Level · AS Level Structured Questions · worked solutions for every part, with the mark scheme

questions

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Topics Work, Energy and Power · Forces, Density and Pressure · Measurement Techniques · Physical Quantities and Units · Dynamics · Deformation of Solids · +5 more

Q1Forces, Density and PressureMeasurement TechniquesPhysical Quantities and UnitsFree sample

Answer all the questions in the spaces provided.

(a)

Define density.

(b)

A smooth pebble, made from uniform rock, has the shape of an elongated sphere as shown in Fig. 1.1.

Fig. 1.1

The length of the pebble is $L$ . The cross-section of the pebble, in the plane perpendicular to $L$ , is circular with a maximum radius $r$ .

A student investigating the density of the rock makes measurements to determine the values of $L$ , $r$ and the mass $M$ of the pebble as follows:

\begin{aligned} L &= (0.1242 \pm 0.0001)\text{ m} \\ r &= (0.0420 \pm 0.0004)\text{ m} \\ M &= (1.072 \pm 0.001)\text{ kg} \end{aligned}

(i)

State the name of a measuring instrument suitable for making this measurement of $L$ .

(ii)

Determine the percentage uncertainty in the measurement of $r$ .

percentage uncertainty = ______ $\%$

(c)

The density $\rho$ of the rock from which the pebble in (b) is composed is given by

\rho = \frac{Mr^n}{kL}

where $n$ is an integer and $k$ is a constant, with no units, that is equal to 2.094.

(i)

Use SI base units to show that $n$ is equal to $-2$ .

(ii)

Calculate the percentage uncertainty in $\rho$ .

percentage uncertainty = ______ $\%$

(iii)

Determine $\rho$ with its absolute uncertainty. Give your values to the appropriate number of significant figures.

$\rho$ = ( ______ $\pm$ ______ ) $\text{kg m}^{-3}$

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5 more questions

Q2Dynamics · Work, Energy and Power11M
Q3Deformation of Solids · Work, Energy and Power10M
Q4Waves · Kinematics9M
Q5D.C. Circuits · Electricity11M
Q6Particle Physics8M

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