Forces | AQA GCSE Physics, Higher tier (8463)

Forces

386 questions
22 subtopics
Paper 2
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, moments, levers and gears, pressure at a surface, and the equation p = F over A, pressure in a column of liquid, upthrust and floating, atmospheric pressure, resolving forces and free body diagrams, 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, braking force, deceleration and the dangers of stopping quickly, momentum and its conservation and changes in momentum.

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.
Work done and energy transfer

How many joules is one newton-metre?

Show the answer
One newton-metre is equal to one joule.
Moments, levers and gears

Write the equation for the moment of a force using symbols.

Show the answer
M = Fd, where M is the moment, F is the force and d is the perpendicular distance from the pivot.
Pressure in a column of liquid, upthrust and floating

What is upthrust?

Show the answer
It is the resultant upward force on a submerged or partly submerged object caused by the pressure difference between its top and bottom surfaces.
Distance, displacement and speed

A cyclist ends a journey 5 km east of the start. State the cyclist's displacement in full.

Show the answer
The displacement is 5 km to the east, giving both the size and the direction.
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.
Newton's First Law

A puck slides across a surface with no resultant force acting on it. What happens to its velocity?

Show the answer
Its velocity stays the same, since neither its speed nor its direction changes.
Stopping distance and reaction time

Calculate the range of the reaction times 0.24 s, 0.28 s and 0.26 s.

Show the answer
Range = 0.28 − 0.24 = 0.04 s.

The 22 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
Moments, levers and gears	Turning effects and how a spanner turns a nut, the moment of a force in words and symbols with its units and the perpendicular distance, why a force through the pivot has no turning effect, balancing about a pivot with seesaw and beam calculations, and how levers and gears transmit the rotational effects of forces.	17
Pressure at a surface, and the equation p = F over A	Fluids and why a gas counts as one, the force from fluid pressure acting at right angles to a surface, the pressure equation in words and symbols with calculations of pressure, force and area, why sharp knives cut and snowshoes stop sinking, and the units of pressure, force and area.	15
Pressure in a column of liquid, upthrust and floating	The quantities and equation for pressure due to a column of liquid, why pressure rises with depth and density, what upthrust is, and why objects float or sink.	17
Atmospheric pressure	The atmosphere and how its density falls with altitude, what causes atmospheric pressure and why it decreases with height, pressurised aircraft cabins, a simple model of the atmosphere, a sealed bottle crushed on the way down a mountain, and why a suction cup stays on a window.	11
Resolving forces and free body diagrams	The forces on a book on a table and a boat crossing a lake, free body diagrams, balanced forces at a steady speed, the resultant of forces that do not act along one line, resolving a force into two components at right angles, and scale diagrams for finding a resultant and showing forces in balance.	12
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 scalars and vectors, changing velocity at constant speed in circular motion, distance–time graphs and finding speed from their gradient, a horizontal line for a stationary object, a curve for an accelerating one, and finding speed at an instant from a curved graph.	16
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, finding acceleration from the gradient of a velocity–time graph, distance travelled from the area under it, and what horizontal and downward-sloping lines show.	21
Area under a velocity-time graph, and the uniform acceleration equation	Finding distance from the area under a curved velocity-time line, the equation linking final velocity, initial velocity, acceleration and distance, free fall at 9.8 m/s², and terminal velocity.	18
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 what inertia means.	14
Newton's Second and Third Laws	How resultant force, mass and acceleration are linked, the units in F = m a, inertial mass, investigating force and acceleration with a trolley, and the equal and opposite forces of Newton's Third Law.	25
Stopping distance and reaction time	Stopping, thinking and braking distance, how speed affects stopping distance and which part is proportional to speed, reading stopping distance data for cars and lorries, how reaction times vary and what lengthens them, the ruler-drop test for reaction time, and why a tired driver has a longer thinking distance.	26
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.	14
Momentum and its conservation	Momentum as mass times velocity in words and symbols with its units and calculations, the momentum of a stationary object, conservation of momentum in a closed system, skaters pushing apart, colliding trolleys and a recoiling rifle, and calculating the common velocity of objects that move off together after a collision.	17
Changes in momentum	How a force changes momentum, combining F = m a with the acceleration equation to give force as rate of change of momentum, and how air bags and other safety features lengthen the time.	12

Forces is 386 of the 1,495 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.