Physical Quantities and Units

Which quantity is a scalar quantity?

Options

A   force
B   momentum
C   velocity
D   work

What is the effect of a systematic error on the measurement of a physical quantity?

Options

A   It limits the precision of the measured value.
B   It limits the range of values obtained in repeated measurements.
C   It results in repeated measurements having different values from each other.
D   It results in the measured value being different from the correct value.

An aircraft, initially stationary on a runway, takes off with a speed of $85\text{ km h}^{-1}$ in a distance of no more than $1.20\text{ km}$.
What is the minimum constant acceleration necessary for the aircraft?

Options

A   $0.23\text{ m s}^{-2}$
B   $0.46\text{ m s}^{-2}$
C   $3.0\text{ m s}^{-2}$
D   $6.0\text{ m s}^{-2}$

Objects P and Q form an isolated system.
Object P has mass $6.0\text{ kg}$ and is moving at a speed of $3.0\text{ m s}^{-1}$.
Object Q has mass $2.0\text{ kg}$ and is moving at a speed of $4.2\text{ m s}^{-1}$ at an angle of $35^\circ$ to the path of P.

Objects P and Q collide and stick together.
What is the magnitude of the component of the final momentum of the combined objects in the original direction of P?

Options

A   $9.6\text{ kg m s}^{-1}$
B   $11\text{ kg m s}^{-1}$
C   $13\text{ kg m s}^{-1}$
D   $25\text{ kg m s}^{-1}$

A student takes measurements to calculate the density of a liquid in a beaker.
The height of the liquid in the beaker is $0.20\text{ m} \pm 2\%$.
The internal diameter of the beaker is $0.05\text{ m} \pm 3\%$.
The mass of the liquid is $0.36\text{ kg} \pm 10\%$.
What is the percentage uncertainty in the calculated density of the liquid?

Options

A   $2\%$
B   $5\%$
C   $15\%$
D   $18\%$

Which quantity is a vector?

Options

A   pressure
B   temperature
C   weight
D   work

Four students, A, B, C and D, have completed an experiment to determine the acceleration of free fall, $g$. Each student repeated the experiment three times. The determined values of $g$ are shown in the table.

Which set of results has a high precision and a low accuracy?

Options

A   A
B   B
C   C
D   D

The diameter of a ball is measured as $(5.26 \pm 0.02)\text{ cm}$.

What is the absolute uncertainty in the volume of the ball?

Options

A   $0.29\text{ cm}^3$
B   $0.87\text{ cm}^3$
C   $1.1\text{ cm}^3$
D   $7.0\text{ cm}^3$

Two vectors, X and Y, are shown.

What are the directions of $\mathbf{X} + \mathbf{Y}$ and $\mathbf{X} - \mathbf{Y}$?

Options

What must all physical quantities have?

Options

A   a direction and a magnitude
B   a direction and a unit
C   a magnitude and a prefix
D   a magnitude and a unit