Forces at KS3

Forces at KS3
A look at some ideas and
activities involved in teaching
Forces at KS3
• To identify key words and ideas at KS3
• To explore practical activities where pupils can
experience and visualise forces both
qualitatively and quantitatively
• To consider and evaluate class management of
practical activities
• To develop clear procedures and rules for
teaching pupils how to analyse forces and
• To consider how and where diagnostic
questions can be used
Forces at KS1 and KS2
They will have learnt about
pushes and pulls
forces produce movement
forces of magnets
forces of springs
forces between Earth, Sun and Moon
balanced and unbalanced forces
Forces at KS3
Pupils should be taught:• Force and linear motion
Gravity and weight
Balanced and unbalanced forces
Frictional forces
• Force and rotation
– Principle of moments
• Force and Pressure
– Pressure = Force/Area
– Applications of pressure
Introducing forces
What do they already know?
How do you engage pupils?
Starter activities
‘Large demonstrations’
Direction of forces
• Force acts at point of contact (bit obvious,
but not always recognised by pupils)
• Examples (lots and lots!)
Measuring forces
• Force-meter/newton-meter
• Measuring forces round the room
• Bathroom scales to measure your weight
in Newtons
• Which leads us on to GRAVITY
• How would you define ‘mass’ and
• The force of gravity on every kg is 10N
approximately here on the Earth’s surface
• Gravity makes things accelerate
downwards all at the same rate
(neglecting air resistance at this point)
• Gravity doesn’t affect forward motion
• Can divide this topic into friction between
solid surfaces and in fluids
• Useful friction and friction as a nuisance
• What happens if there is no friction?
• Terminal velocity
• Experiments to remember
Forces and linear motion
• What do we mean by ‘balanced and
unbalanced’ forces?
• Balanced forces = constant motion (or
• Unbalanced forces = changing motion
• Measuring speed
Forces and pressure
• Pressure = Force/Area
• Units?
• Demonstrating the effect of changing the
area acted on
• Measuring pressure on the ground made
by our feet
Turning forces or moments
• “Give me a lever and I can move the
• Clockwise and anticlockwise moments
• Examples of moments in action
Summary of forces topics
Introduction to forces
Direction and measuring forces
Forces and motion
Forces and pressure
Turning forces and moments