Edexcel Physics IGCSE
Forces and Motion
Revision Notes
Movement and position
Speed is defined as the ……………………..
𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑠𝑝𝑒𝑒𝑑 =
Velocity is the ……………………………….
Acceleration is the …………………………..
𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 =
Distance is measured in ……….. (m), time in seconds (s), speed and velocity in
…………………….. (m/s), and acceleration in ……………………… (m/s2).
In a distance-time graph:
The gradient is …………………………..
o Negative gradient is returning back to the
starting point
A horizontal line means it is ……………………
If the distance is zero, it is back at the starting
point
A curved line means that the …………is changing,
and it is ……………………..
In a velocity-time graph:
The gradient is ………………….
o Negative gradient (i.e. negative
acceleration) is deceleration
If the speed is zero, it is at rest
A horizontal line means …………………….
The area under the line is the ………………. travelled
Forces, movement, shape and momentum
Vectors & scalars:
A vector has …………………………………..
A scalar has just
.Examples:
Scalars Vectors
Distance Displacement
Speed Velocity
Time Acceleration
Energy Force
Effects of forces:
Forces can change the …………………. or ……………. of a body and they are measured in Newtons (N).
There are various different types of forces (e.g. gravitational, electrostatic).
Friction is a force between two surfaces which ………………….. and results in heating. Air
resistance is a form of friction.
To find the resultant of two or more forces acting along the same
line, they should be added together if in the …………………. and
……………….. if in the ……………direction.
Mass is a measure of how much matter is in an object, measured in kilograms (kg). ……………. is
a gravitational force (the effect of a gravitational field on a mass).
𝑤𝑒𝑖𝑔ℎ𝑡 = 𝑚𝑎𝑠𝑠 × 𝑔𝑟𝑎𝑣𝑖𝑡𝑎𝑡𝑖𝑜𝑛𝑎𝑙 𝑓𝑖𝑒𝑙𝑑 𝑠𝑡𝑟𝑒𝑛𝑔𝑡ℎ 𝑊 = 𝑚………….
The gravitational field strength on Earth is 10N/kg.
The weight of an object acts through its ……………………of gravity.
An apple has a mass of 100 g. Calculate its weight on Earth (g = 9.8 N/kg).
When a driver notices a hazard:
The distance travelled in the time between the driving realising he needs to brake and
actually pressing the brakes is called the …………………….. Factors which increase the
thinking distance include:
o Greater ………………………
o Slower reaction time due to alcohol, tiredness or distractions. Reaction time
can also be increased by caffeine, which reduces the thinking distance.
The distance travelled in the time between pressing the brakes and the vehicle coming to
a stop is called the …………………… distance. Factors which increase the stopping distance
include:
o Greater speed or mass
o Poor ……………………………….. (icy, wet) or ………………………… (worn tires, worn brake
pads)
The ……………………………… distance is the sum of the thinking distance and braking distance.
stopping distance=thinking distance +braking distance
Questions
Graph 1
Which sections of the graph show that the object is…
Stationary?
_________________________________________________________________________
Moving at a constant speed?
_________________________________________________________________________
Moving with increasing speed?
_________________________________________________________________________
Moving with decreasing speed?
_________________________________________________________________________
Moving with the greatest speed?
_________________________________________________________________________
Calculate the gradient of the line AB
____________________________________________
Calculate the gradient of the line CD
____________________________________________
Calculate the gradient of the line DE
____________________________________________
Which sections of the graph show that the object is…
Stationary?
_________________________________________________________________________
Moving at a constant speed?
_________________________________________________________________________
Moving with increasing speed?
_________________________________________________________________________
Moving with decreasing speed?
_________________________________________________________________________
Moving with the greatest speed?
_________________________________________________________________________
Calculate the gradient of the line 0A
____________________________________________
Calculate the gradient of the line AB
____________________________________________
Calculate the gradient of the line CD
____________________________________________
Calculate the gradient of the line DE
____________________________________________
Graph 3
Which sections of the graph show that the object is…
Stationary?
_________________________________________________________________________
Moving at a constant speed?
_________________________________________________________________________
Moving with increasing speed?
_________________________________________________________________________
Moving with decreasing speed?
_________________________________________________________________________
Calculate the gradient of BC ____________________________________________
Calculate the area under the graph____________________________________________
Graph 4
Which sections of the graph show that the object is…
Stationary?
_________________________________________________________________________
Moving at a constant speed?
_________________________________________________________________________
Moving with increasing speed?
_________________________________________________________________________
Moving with decreasing speed?
_________________________________________________________________________
Calculate the gradient of line W ____________________________________________
Calculate the gradient of line X ____________________________________________
Calculate the gradient of line Z ____________________________________________
Calculate the area under Y ____________________________________________
For each of the following situations calculate the resultant force and describe what would happen to
the object:
A) The object is initially stationary
Resultant Force: Size _____________________ Direction
B) The object is initially stationary
Resultant Force: Size _____________________ Direction
C) The object is initially stationary
Resultant Force: Size _____________________ Direction
D) The object is initially moving to the right
Resultant Force: Size _____________________ Direction
E) The object is initially moving to the right
Resultant Force: Size _____________________ Direction
F) The object is initially moving to the right
Resultant Force: Size _____________________ Direction
G) The object is initially moving to the left
Resultant Force: Size _____________________ Direction
Thinking distance is ……………………………………………………………………………………………...……..
Braking distance is ……………………………………………………………………………………………....……..
Stopping distance is ……………………………………………………………………………………………..……..
List factors that affect the thinking distance.
List factors that affect the braking distance.
Some factors that would increase a driver’s reaction time are:
What would increasing the reaction time do to the following?
Thinking distance ……………………………….….……
Braking distance …………………………….…….……
Stopping distance …………………………….…….……
