WorksheetsAS 1.1 Physical Quantities & Units
Total questions: 30
Worksheet time: 15mins
Name
Class
Date
1.
Question 1
Which of the following is an SI base unit?
a)
A Current
b)
B Gram
c)
C Kelvin
d)
D Volt
2.
Question 2
Which definition is correct and uses only quantities rather than units?
a)
A Density is mass per cubic metre
b)
B Potential difference is energy per unit current
c)
C Pressure is force per unit area
d)
D Speed is distance travelled per second
3.
Question 3
Five energies are listed below.
5 kJ
5 mJ
5 MJ
5 nJ
Starting with the smallest first, what is the order of increasing magnitude of these energies?
a)
A 5kJ→5mJ→5MJ→5nJ
b)
B 5nJ→5kJ→5MJ→5mJ
c)
C 5nJ→5mJ→5kJ→5MJ
d)
D 5mJ→5nJ→5kJ→5MJ
4.
Question 4
What is a reasonable estimate of the average gravitational force acting on a fully grown woman standing on the Earth?
a)
A 60 N
b)
B 250 N
c)
C 350 N
d)
D 650 N
5.
Question 5
Which product-pair of metric prefixes has the greatest magnitude?
a)
A pico x mega
b)
B nano x kilo
c)
C micro x giga
d)
D milli x tera
6.
Question 6
Which pair contains one vector and one scalar quantity?
a)
A displacement acceleration
b)
B force kinetic energy
c)
C momentum velocity
d)
D power speed
7.
Question 7
Which statement includes a correct unit?
a)
A energy = 7.8 Ns
b)
B force = 3.8 Ns
c)
C momentum = 6.2 Ns
d)
D torque = 4.7 Ns
8.
Question 8
Which quantity can be measured in electronvolts (eV)?
a)
A electric charge
b)
B electric potential
c)
C energy
d)
D power
9.
Question 9
Two physical quantities P and Q are added together. The sum of P and Q is R, as shown in the diagram.
Which quantity could be represented by P and by Q?
a)
A kinetic energy
b)
B power
c)
C speed
d)
D velocity
10.
Question 10
The arrow represents the vector R.
Which diagram does not represent R as two perpendicular components?
a)
A
b)
B
c)
C
d)
D
11.
Question 11
The average kinetic energy E of a gas molecule is given by the equation :
E= (3 /2) kT
where T is the absolute (kelvin) temperature.
What are the SI base units of k?
a)
A kg⁻¹ m⁻¹ s² K
b)
B kg⁻¹ m−² s² K
c)
C kg m s−² K⁻¹
d)
D kg m² s−² K⁻¹
12.
Question 12
The speed of an aeroplane in still air is 200 km h⁻¹. The wind blows from the west at a speed of 85.0 km h⁻¹.
In which direction must the pilot steer the aeroplane in order to fly due north?
a)
A 23.0° east of north
b)
B 23.0° west of north
c)
C 25.2° east of north
d)
D 25.2° west of north
13.
Question 13
The units of all physical quantities can be expressed in terms of SI base units.
Which pair contains quantities with the same base units?
a)
A force and momentum
b)
B pressure and Young's modulus
c)
C power and kinetic energy
d)
D mass and weight
14.
Question 14
Vectors P and Q are drawn to scale.
Which diagram represents the vector (P – Q)?
a)
A
b)
B
c)
C
d)
D
15.
Question 15
The table contains some quantities, together with their symbols and units.
quantity symbol unit
gravitational field strength g N kg⁻¹
density of liquid ρ kg m⁻³
vertical height h m
volume of part of liquid V m³
Which expression has the units of energy?
a)
A ρ g² h
b)
B ρ h V/g
c)
C ρ g/ (hV)
d)
D g ρ h V
16.
Question 16
What is the ratio 10⁻³ THz / 10³ kHz ?
a)
A 10⁻⁹
b)
B 10⁻⁶
c)
C 10⁰
d)
D 10³
17.
Question 17
Which of the following correctly expresses the volt in terms of SI base units?
a)
A A Ω
b)
B W A⁻¹
c)
C kgm² s⁻¹ A⁻¹
d)
D kgm² s⁻³ A⁻¹
18.
Question 18
A vector has magnitude R and perpendicular components P and Q, as shown in the diagram.
Which row correctly describes the perpendicular components?
a)
A Q sin Θ
b)
B R cos Θ P
c)
C R cos Θ R sin Θ
d)
D R sin Θ R cos Θ
19.
Question 19
For which quantity is the magnitude a reasonable estimate?
a)
A Frequency of a radio wave 500p Hz
b)
B Mass of an atom 500 μg
c)
C The Young modulus of a metal 500 kPa
d)
D Wavelength of green light 500 nm
20.
Question 20
The equation relating pressure and density is P=ρgh
How can both sides of this equation be written in terms of base units?
a)
A [N m⁻¹] = [kg m-3] [m s⁻¹] [m]
b)
B [N m⁻²] = [kg m⁻²] [m s⁻²] [m]
c)
C [kg m⁻¹ s⁻²] = [kg m⁻³] [m s⁻²] [m]
d)
D [kg m⁻¹ s⁻¹] = [kg m⁻¹] [m s⁻²] [m]
21.
Question 21
The speed v of a liquid leaving a tube depends on the change in pressure ΔP and the density ρ of the liquid. The speed is given by the equation
where k is a constant that has no units.
What is the value of n?
a)
A 1/2
b)
B 1
c)
C 3/2
d)
D 2
22.
Question 22
Which estimate is realistic?
a)
A The kinetic energy of a bus travelling on an expressway is 30,000 J
b)
B The power of a domestic light is 300 W
c)
C The temperature of a hot oven is 300 K
d)
D The volume of air in a car tyre is 0.03 m³
23.
Question 23
Which statement is incorrect by a factor of 100 or more?
a)
A Atmospheric pressure is about 1 × 10⁵ Pa
b)
B Light takes 5 × 10² s to reach us from the Sun
c)
C The frequency of ultraviolet light is 3 × 10¹² Hz
d)
D The life-span of a man is about 2 × 10⁹ s
24.
Question 24
The frictional force F on a sphere falling through a fluid is given by the formula
F=6π a η v
where a is the radius of the sphere, η is a constant relating to the fluid and v is the velocity of the sphere.
What are the units of η ?
a)
A kg m s⁻¹
b)
B kg m⁻¹ s⁻¹
c)
C kg m s⁻³
d)
D kg m³ s⁻³
25.
Question 25
When a constant braking force is applied to a vehicle moving at speed v, the distance d moved by the vehicle as it comes to rest is given by the expression
d = k v ²
where k is a constant.
When d is measured in metres and v is measured in metres per second, the constant has a value of k₁.
What is the value of the constant when the distance is measured in metres, and the speed is measured in kilometres per hour?
a)
A 0.0772 k₁
b)
B 0.278 k₁
c)
C 3.60 k₁
d)
D 13.0 k₁
26.
Question 26
The drag coefficient C is a number with no units. It is used to compare the drag on different cars at different speeds. It is given by the equation
where F is the drag force on the car, ρ is the density of the air, A is the cross-sectional area of the car and v is the speed of the car.
What is the value of n?
a)
A 1
b)
B 2
c)
C 3
d)
D 4
27.
Question 27
Two forces, each of 10 N, act at a point P as shown in the diagram. The angle between the force vectors is 120°
What is the magnitude of the resultant force?
a)
A 5 N
b)
B 10 N
c)
C 17 N
d)
D 20 N
28.
Question 28
Which formula could be correct for the speed v of ocean waves in terms of the density ρ of sea-water, the acceleration of free fall g, the height h of the wave and the wavelength λ?
a)
A v = √(ρ g h)
b)
B v = √( g/h)
c)
C v = √( gλ)
d)
D v = √( g/ρ)
29.
Question 29
The diagrams represent systems of coplanar forces acting at a point.
The lengths of the force vectors represent the magnitudes of the forces. Which system of forces is in equilibrium?
a)
A
b)
B
c)
C
d)
D
30.
Question 30
A glider is descending at a constant speed at an angle of 15° to the horizontal.
The diagram shows the directions of the lift L, air resistance R and weight W acting on the glider.
Which vector triangle could represent the forces acting on the glider?
a)
A
b)
B
c)
C
d)
D
100 %
