Forces | AQA GCSE Combined Science Trilogy Physics, Foundation tier (8464)

Forces

264 questions
15 subtopics
Physics Paper 2
Physics Paper 2

Forces is examined in Physics Paper 2.

It covers scalars, vectors, forces and the resultant force, gravity, work done and energy transfer, stretching, compressing, and the spring constant, linear and non-linear extension, and work done on a spring, distance, displacement and speed, the speed of sound, and the distance-speed-time equation, velocity and the distance-time relationship, acceleration, deceleration and velocity-time graphs, area under a velocity-time graph, and the uniform acceleration equation, Newton's First Law, Newton's Second and Third Laws, stopping distance and reaction time, factors affecting braking distance and braking force, deceleration and the dangers of stopping quickly.

Sample questions from Forces

Answer each one closed book first, then open the answer.

Scalars, vectors, forces and the resultant force

What is a force?

Show the answer
A force is a push or a pull acting on an object because of its interaction with another object.
Gravity

Where does the weight of a uniform metre rule act?

Show the answer
At its centre of mass, which is the midpoint of the rule.
Stretching, compressing, and the spring constant

State the relationship between the extension of a spring and the force applied to it.

Show the answer
The extension is directly proportional to the force applied, provided the limit of proportionality is not exceeded.
Linear and non-linear extension, and work done on a spring

What is meant by an accurate measurement?

Show the answer
One that is close to the true value.
The speed of sound, and the distance-speed-time equation

A cyclist rides at a constant 6 m/s for 40 s. Calculate the distance travelled.

Show the answer
The distance is 240 m, from 6 m/s × 40 s.
Velocity and the distance-time relationship

What does a horizontal line on a distance–time graph tell you about the object?

Show the answer
The object is stationary, because the distance is not changing as time passes.
Area under a velocity-time graph, and the uniform acceleration equation

A train travelling at 30 m/s decelerates uniformly at 0.5 m/s² over 500 m. Calculate its velocity at the end of that distance.

Show the answer
Its velocity is 20 m/s, because v² = 900 − 2 × 0.5 m/s² × 500 m = 400.
Newton's First Law

Under what condition will the velocity of an object change?

Show the answer
Only when a resultant force acts on the object.

The 15 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
Scalars, vectors, forces and the resultant force	Scalar and vector quantities and why velocity is a vector, representing vectors with arrows, contact and non-contact forces with examples of each, force as a vector and the pair of forces produced when two objects interact, and finding the resultant of forces acting along a straight line.	22
Gravity	Weight and why objects near the Earth have it, how weight depends on mass and gravitational field strength, the equation W = mg in words and symbols with calculations, the units of weight, mass and gravitational field strength, centre of mass, weight in direct proportion to mass, and measuring weight with a newtonmeter.	18
Work done and energy transfer	When work is and is not done on an object, the equation for work done in words and symbols with calculations, the units of work, force and distance, the joule and the newton-metre, the energy transfer when a crane lifts a load, and how work done against friction heats a car's brakes.	17
Stretching, compressing, and the spring constant	The forces that stretch, compress and bend objects, elastic and inelastic deformation, extension proportional to force up to the limit of proportionality, the equation linking force, spring constant and extension with its units, compressing rather than stretching, and the elastic potential energy stored as work is done on a spring.	18
Linear and non-linear extension, and work done on a spring	Finding the spring constant from force and extension or from a graph, what linear and non-linear mean, the energy stored in a stretched spring, and a method for investigating extension.	26
Distance, displacement and speed	Distance as a scalar and displacement as a vector with magnitude and direction, speed as a scalar that rarely stays constant, the factors affecting how fast people walk, run and cycle, typical speeds for walking, running, cycling, cars and aeroplanes, and other things whose speed varies.	18
The speed of sound, and the distance-speed-time equation	A typical speed of sound in air, measuring speed from distance and time, the equation s = v t in words and symbols with its units and calculations, rearranging it for time, and calculating average speed for journeys in which the speed keeps changing.	16
Velocity and the distance-time relationship	Velocity as speed in a given direction and how it differs from speed, sorting distance, displacement, speed and velocity into scalars and vectors, what a distance–time graph represents, finding speed from its gradient, a horizontal line for a stationary object, the quantity on each axis, and calculating speed from a straight line.	12
Acceleration, deceleration and velocity-time graphs	The equation for average acceleration with its units and the meaning of ∆v, deceleration and negative acceleration, estimating the accelerations of a sprinter and a car, the axes of a velocity–time graph, finding acceleration from its gradient, and what horizontal and downward-sloping lines show.	18
Area under a velocity-time graph, and the uniform acceleration equation	When the equation linking final velocity, initial velocity, acceleration and distance applies, the equation in words and in the symbols v, u, a and s with its units and calculations, free fall at 9.8 m/s² and the speed of a dropped stone, and how an object falling through a fluid reaches terminal velocity as the resultant force becomes zero.	14
Newton's First Law	What Newton's First Law says about zero resultant force, what happens to stationary and moving objects when forces balance, why a car reaches a top speed and a cyclist who stops pedalling slows down, and the resultant force needed to change speed or direction, as on a bend.	12
Newton's Second and Third Laws	How resultant force, mass and acceleration are linked, the equation F = m a with its units, estimating the force to accelerate a car and what the wavy approximation symbol means, investigating force, mass and acceleration with a trolley, and the equal and opposite forces of Newton's Third Law.	22
Stopping distance and reaction time	Stopping, thinking and braking distance, how an increase in speed affects stopping distance, how reaction times vary and the things that lengthen them, measuring reaction time with a ruler-drop test and repeating it, and why a tired driver has a longer thinking distance.	22
Factors affecting braking distance	The factors that lengthen braking distance, including icy and wet roads and worn brakes and tyres, whether heavy rain affects thinking or braking distance, leaving a bigger gap in icy weather, checking tyre tread, lower speed limits outside schools, and estimating braking distance when speed doubles or the road is wet.	16
Braking force, deceleration and the dangers of stopping quickly	The energy transfer when brakes are applied, how speed affects the braking force needed, how braking force sets deceleration, and the dangers of overheating brakes, skidding and large forces on passengers.	13

Forces is 264 of the 994 questions in the guide.Get the guide, £7

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.