Module 3: Forces and Motion
The forces and motion module is all taught in year 12 and forms half of Modelling Physics. The topic builds on your GCSE knowledge of forces and motion and it is essential that you have a good grasp of this before starting the A Level course. Visit the "Preparing for A Level" section for more information.
The forces and motion module is split in to 5 submodules:
3.1 Motion and 2.0 Uncertainty analysis
By the end of this topic you should be able to:

Describe the difference between accuracy and precision and random and systematic error

Calculate and combine percentage and absolute uncertainties

Construct error bars and lines of worst fit to establish uncertainty in a gradient

Calculate percentage difference

Define and calculate displacement, instantaneous speed, average speed, velocity and acceleration

Describe features of distancetime and displacementtime graphs and calculate the gradient to find velocity (including for nonlinear graphs)

Describe features of speedtime and velocitytime graphs and calculate the gradient to find acceleration and area underneath to find total distance/displacement (including for nonlinear graphs)

Use the equations of motion in calculations

Describe methods to measure acceleration of freefall (g)

Define and explain factors that affect stopping distance, thinking distance and braking distance

Calculate variables in projectile motion by splitting into horizontal and vertical components of motion
3.2 Forces & 3.5 Newton's Laws and momentum
By the end of this topic you should be able to:â€‹
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Describe how force, mass and acceleration are linked

Describe the difference between weight and mass, and describe how to find the centre of mass

State different types of force and describe how these act on objects

Describe how drag forces act in fluids so objects reach terminal velocity including an experiment to demonstrate this

Define what is meant by density and pressure and use this to describe pressure in fluids and Archimedes’ principle

Construct free body diagrams

Resolve forces to find a resultant force and resolve forces into components

Define the principle of moments and calculate moments

Define torque and calculate this for objects

State and explain Newton’s three laws of motionâ€‹

Calculate momentum

Define the principle of conservation of momentum and use this to calculate change in momentum during collisions and explosions

Define what is meant by impulse and link this to forcetime graphs

Describe what is meant by elastic and inelastic collisions

Solve problems involving change in momentum in two dimensions
3.3 Work, energy and power
By the end of this topic you should be able to:â€‹
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Describe different types and transfers of energy

Calculate and define work done, including for forces at angles

Derive the equation for kinetic energy and use this in calculations

Derive the equation for gravitational potential energy and use this in calculations

Complete calculations involving energy transfers between gravitational and kinetic energy

Define and calculate power

Calculate efficiency of energy transfers
3.4 Materials
By the end of this topic you should be able to:
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Define and describe Hooke’s law and how this varies for springs in series and parallel

Describe what the force constant for a spring or a wire is and how this can be found experimentally

Describe the difference between elastic and plastic deformation and how this is shown on forceextension graphs

Describe what is meant by elastic potential energy and calculate this from the equation and graphs

Define and calculate; stress, strain and Young’s Modulus and explain what is meant by ultimate tensile strength

Describe how you would experimentally find the Young’s modulus of a metal

Describe the terms ductile and brittle and how stressstrain graphs look for these materials and polymetric materials