Force in the early years/Document

At KS1 pupils needs to be able to:

• describe the movement of familiar things,
• know that pushes and pulls are examples of forces,
• know that forces can make things speed up, slow down or change direction and can change the shape of objects.

At KS1 we’re building up the language of forces (push and pull) and introducing what forces can do. This can be one of the most creative and enjoyable areas of early years science, although it is one of the ones which people find the most daunting.

Taking a statement at a time:

Describe the movement of familiar things

The most ‘familiar moving thing’ which children can describe is themselves. Use P.E. activities to introduce and reinforce vocabulary: start, stop, speed up, slow down, turn, spin, right and left, twirl, roll, skip, etc.

Here are some more examples:

• Car mat activity: describing the movement of toy cars as they are played with watching traffic – links to road safety.
• Moving things in the classroom: twirlers, mobiles.
• Using musical instruments to describe movement, e.g. swanee whistle, also describing pushes and pulls.

Know that pushes and pulls are examples of forces

NB. It is important to talk about ‘big’ and ‘small’ pushes and pulls.

• Getting dressed/sewing/weaving.
• Printing / making shallow and deep impressions in soft dough using fingers or objects
• Push and pull around the classroom: doors, drawers, windows/push and pull toys/puppets.
• Talk about big machines such as diggers.
• Prams/bikes, etc.
• Swings and other playground activities.
• Skittles/jumping toys/falling dominoes/finger paint.

Know that forces can make things speed up, slow down or change direction

Again, compare the effects of ‘big’ and ‘small’ forces.

• Moving air: windmills/ribbons/kites/racing wind wheels/bubbles/wind chimes/wind measurers (different materials on washing lines)/wind sock/spiral twirlers/flapping fish race/sails on modern ships/squirting bottles/battery fans/pneumatics (demonstrate a simple syringe effect)/balloon on string/car (demonstrate)/blow paint.
• Moving water: water wheels/car or boat water toys.
• Screwball scramble/marble in paint/ramps/marble run.

Know that forces can change the shape of objects.

Dough/salt dough/clay/making biscuits/bendy toys/elastic things /stretchy things/springy things – bouncy balls/paper springs. Any work on forces must take into account the children’s prior knowledge of forces. It is important to realise that the way in which the word ‘force’ is used in everyday life can cause problems for children when considering forces in a scientific context. Point out misconceptions: force is not ‘energy’, it does not have to be ‘big and strong’.

At KS2 the NC is broken down into:

• types of forces and their effects: magnetic, gravitational, friction including air resistance, forces in springs and elastic bands.
• balanced and unbalanced forces: forces act in a particular direction, can be balanced e.g. tug-of-war, unbalanced forces can make things speed up, slow down or change direction.

Thus at KS2 we are concerned with the effects of specific types of forces and the direction in which forces act.

Points to follow up

Pressure= force ÷ area

If someone stands on your toes wearing stiletto heels, it is more painful than if they do so wearing wellies. The same force is applied over a smaller area. This also explains why it is important to lie on a ladder if you are rescuing someone trapped in a frozen pond. Your pressure on the ice will be less because your weight (force) will be spread over a larger area.

Energy = force x distance

The same energy is required to close a door however you do it. If you close it with your hand near the hinge, it is hard work. A large force is needed because the distance is small. If you close it with your hand near the handle it is much easier. Less force is needed because the distance is greater.

Force + mass x acceleration

In other words, the harder we push, the more things will speed up. Force is directly proportional to acceleration. If we were to rearrange this formula:

Acceleration = force
—−—−—−
mass

Then we can see that acceleration is inversely proportional to the mass of an object. The bigger the object the harder we would have to push to get it to speed up.

Friction is force

It is the force resisting motion between two surfaces in contact. Air resistance is a kind of friction.

Demonstrations

Force toys in variety including a screwball scramble, windsocks, windmills, twirly things and marble run/Galt Ramp equipment/Pneumatic kit/Balloon on string.

Activities

Explore toys: make a list and identify which aspects of forces that could be used.

Definitions

A force is when you’re made to do something. My mother forces me to tidy the room when I don’t want to. Forces are big and strong Forces are power and energy. When it snows and it’s cold and there’s snow everywhere, you have to force your way through. I am not sure what force means but there’s an Air Force. It’s got a blue uniform. There’s also brute force. Force is gravity and wind. (Sparks 1993 PSR 28)

Mass is a measure of the ‘amount of stuff’. Mass is measured in grams (g) and kilograms (kg). Weight is the measure of the ‘pull of gravity’. Weight is a force measured in Newtons (N). A mass of 1kg has a weight of about 10N. On the earth, the pull of gravity is about 10N. On the moon, the pull of gravity is about 1/6 of that on earth. If your mass is 30kg on the earth it is also 30kg on the moon. Your weight on the earth will be 300N but on the moon it will only be 50N.