1 Motion, forces and energy

1.1 Physical quantities and measurement techniques

Core Suppli?ment
Describe the use of rulers and measuring
cylinders to find a length or a volume
2 Describe how to measure a variety oftime
intervals using clocks and digital timers
3 Determine an average value for a small distance
and for a short interval of time by measuring
multiples (including the period of oscillation of a
pendulum)
4 Understand that a scalar quantity has magnitude
(size) only and that a vector quantity has
magnitude and direction
S Know that the following quantities are scalars:
distance, speed, time, mass, energy and
temperature
6 Know that the following quantities are vectors:
force, weight, velocity, acceleration, momentum,
electric field strength and gravitational field
strength
7 Determine, by calculation or graphically, the
resultant of two vectors at right angles, limited
to forces or velocities only

1.2 Motion

C. ft." Supplern,•nt
Define speed as distance travelled per unft tfme;
recall and use the equation
V= •
s
t
2 Define velocity as speed in a given direction
3 Recall and use the equation 9 Define acceleration as change in velocity per unit
d total dfstance travelled 'time; recall and use the equation
average spee "' total time taken t:,.v
a= -
4 Sketch, plot and interpret distance-time and 6!
speed-time graphs
S Determine, qualitatively, from given data or the 10 Determine from given data or the shape of a
shape of a distance-time graph or speed- time speed-time graph when an object Is moving with:
graph when an object is: (a)1 constant acceleration
(a) at rest (b) changing acceleration
(b) moving with constant speed
(c) accelerating
(d) decelerating
6 Calculate speed from the gradient of a strafght- 11 Calculate acceleration from the gradient of a
line section of a distance-time graph speed-time graph
7 Calculate the area under a speed-time graph to
determine the distance travelled for motion with
constant speed or constant acceleration
12 Know that a deceleration is a negative
acceleration and use this In calculations
8 State that the acceleration of free fall g for 13 Describe the motion of objects falling in a
an object near to the surface of the Earth is uniform gravitational field with and without air/
approximately constant and is approximately liquid resistance (including reference to terminal
9.8 m/s2 velocity)
1.3 Mass and weight

Core Supplement
State that mass is a measure of the quantity
of matter in an object at rest relative to the
observer
2 State that weight is a gravitational force on an 5 Describe, and use the concept of, weight as the
object that has mass effect of a gravitational field on a mass
3 Define gravitational field strength as force per
unit mass; recall and use the equation

g=;;;w
and know that this is equivalent to the
acceleration of free fall
4 Know that weights (and masses) may be
compared using a balance

1.4 Density

Core Supplement
Define density as mass per unit volume; recall
and use the equation

p=vm
2 Describe how to determine the density of a
liquid, of a regularly shaped solid and of an
irregularly shaped solid which sinks in a liquid
(volume by displacement), including appropriate
calculations
3 Determine whether an object floats based on 4 Determine whether one liquid will float on
density data another liquid based on density data given that
the liquids do not mix

1.5 Forces

1.5.1 Effects of forces

Core Supplement
Know that forces may produce changes in the 9 Define the spring constant as force per unit
size and shape of an object extension; recall and use the equation
k= E_
X

2 Sketch, plot and interpret load-extension graphs 10 Define and use the term 'limit of proportionality'
for an elastic solid and describe the associated for a load-extension graph and identify this point
experimental procedures on the graph (an understanding of the elastic
limit is not required)
3 Determine the resultant of two or more forces 11 Recall and use the equation F =ma and know
acting along the same straight line that the force and the acceleration are in the
same direction
4 Know that an object either remains at rest or
continues in a straight line at constant speed
unless acted on by a resultant force
5 State that a resultant force may change the 12 Describe, qualitatively, motion in a circular path
velocity of an object by changing its direction of due to a force perpendicular to the motion as:
motion or its speed
(a) speed increases if force increases, with mass
and radius constant
(b) radius decreases if force increases, with mass
and speed constant
(c) an increased mass requires an increased force
to keep speed and radius constant
2
(F = ~ is not required)
r
continued
1.5 Forces continued

1.5.1 Effects of forces continued

Supplement
6 Describe solid friction as the force between two
surfaces that may impede motion and produce
heating
7 Know that friction (drag) acts on an object
moving through a liquid
8 Know that friction (drag) acts on an object
moving through a gas (e.g. air resistance)

1.5.2 Turning effect of forces

(ore Supplement
Describe the moment of a force as a measure of
its turning effect and give everyday examples
2 Define the moment of a force as
moment= force x perpendicular distance from
the pivot; recall and use this equation
3 Apply the principle of moments to situations S Apply the principle of moments to other
with one force each side of the pivot, including situations, including those with more than one
balancing of a beam force each side of the pivot
4 State that, when there is no resultant force and 6 Describe an experiment to demonstrate that
no resultant moment, an object Is in equilibrium there Is no resultant moment on an object in
equilibrium

1.5.3 Centre of gravity

C ,re Supplement
1 State what is meant by centre of gravity
2 Describe an experiment to determine the
position of the centre of gravity of an irregularly
shaped plane lamina
3 Describe, qualitatively, the effect of the position
of the centre of gravity on the stability of simple
objects

1.6 Momentum
Core Supplement
1 Define momentum as mass x velocity; recall and
use the equation
p=mv
2 Define impulse as force x time for which force
acts; recall and use the equation
impulse = F!1c = 11(mv)
3 Apply the principle of the conservation of
momentum to solve simple problems in one
dimension
4 Define resultant force as the change in
momentum per unit time; recall and use the
equation
F= ~
~t
 1.7 Energy, work and power

1.7.1 Energy

CorE Supplement
State that energy may be stored as kinetic,
gravitational potential, chemical, elastic (strain),
nuclear, electrostatic and internal (thermal)
2 Describe how energy is transferred between
stores during events and processes, including
examples of transfer by forces (mechanical work
done). electrical currents (electrical work done).
heating. and by electromagnetic, sound and
other waves
4 Recall and use the equation for kinetic energy
fk =½mv2
S Recall and use the equation for the change in
gravitational potential energy

Mp=mgM
3 Know the principle of the conservation of energy 6 Know the principle of the conservation of
and apply this principle to simple examples energy and apply this principle to complex
including the interpretation of simple flow examples involving multiple stages, including the
diagrams interpretation of Sankey diagrams

14 www.cambridgeinternational.org/igcse Back to contents page

Cnmbrrdg• IGCSE Physrcs 0625 ,yllabu, for 2023. 1024 and 2025 Subiect cont,nt

1.7 Energy, work and power continued

1.7.2 Work

Cor~ Supplement
Understand that mechanical or electrical work
done is equal to the energy transferred
2 Recall and use the equation for mechanical
working
W •Fd•M

1.7.3 Energy resources

Core Supplem,•nt
Describe how useful energy may be obtained, or 4 Know that radiation from the Sun is the main
electrical power generated, from: source of energy for all our energy resources
except geothermal, nuclear and tidal
(a) chemical energy stored in fossil fuels
(b) chemical energy stored in biofuels
(c) water, including the energy stored in waves,
in tides, and in water behind hydroelectric
dams
(d) geothermal resources
(e) nuclear fuel
(f) light from the Sun to generate electrical
power (solar cells)
(g) infrared and other electromagnetic waves
from the Sun to heat water (solar panels) and
be the source of wind energy
including references to a boiler, turbine and
generator where they are used
2 Describe advantages and disadvantages of each 5 Know that energy is released by nuclear fusion in
method in terms of renewability, availability, the Sun
reliability, scale and environmental impact
6 Know that research is being carried out to
investigate how energy released by nuclear fusion
can be used to produce electrical energy on a
large scale