Forces are all around us and affect everything we do, with that in mind we’ve put together a collection of ideas for learning about forces with something for everyone from preschoolers to grown ups.
Lets start with some basics.
What is a force?
A force is a push or a pull. Forces can make object moves or stop, speed them up or slow them down. If you push a toy car it moves, if you push it harder it moves faster. Forces can also make objects change direction or shape.
A lighter object needs less force to move than a heavier object. For example you could push a n empty box easily, but a filled box would be harder, it would need more force to move.
If you give a toy car a push what happens? It speeds up and then slows down. The reason it slows down is because of two forces, air resistance and friction.
Air resistance is air pushing on a moving object which slows it down.
Friction is the force between two objects when you rub them together. Try rubbing your hands together? Do they get hot? You feel the friction between your hands as heat.
Air resistance and friction take time to slow an object down, if you want an object to stop quickly you need to apply further force, for example a brake on a bike.
Other examples of forces are magnetism, gravity and air pressure.
Over the years we’ve completed lots of forces experiments on Science Sparks, here are the best ones.
Learn about simple pushes and pulls in this easy activity.
Find out why you slip and slide more on smooth surfaces than rougher surfaces with this slipping and sliding activity. Do be careful not to fall over though.
Discover why we salt/grit icy roads in winter.
Try this fun Gravity Experiment from Inspiration Laboratories.
Making vehicles move
We used Carbon Dioxide released from a baking soda and vinegar reaction to power a bottle boat.
Slightly more simple and much more powerful is our balloon powered LEGO car.
Red Ted Art made a fun elastic powered tugboat which moves using the energy stored when you wind up an elastic band.
Learn about reducing friction with this easy Hovercraft.
Make an easy magnet maze.
Make a parachute, can you save an egg?
Watch a boiled egg drop into a jar with a bit of science magic.
Make a bottle rocket, remember you need lots of space for this one.
Watch water rise with this cool air pressure experiment.
Pop the lid off a bottle with these coin poppers.
Make these shooters and explore trajectory and aerodynamics.
How about a film canister rocket?
Drop water balloons filled with paint and compare splatter patterns from different heights.
Explore energy and ‘bouncy-ness’ with some balls and different surfaces.
Try this fun conker investigation, using forces to break the conker.
Why do you get dizzy on a roundabout? It’s all about the forces.
How about building some stable structures and investigating the ‘force’ needed to knock them over?
You could investigate the force needed to break an eggshell.
Finally, do you know why a balloon makes a funny noise when you let it go?
We’ll be adding to this list all the time so do keep popping back.
Tagged: ForcesKey Stage 1 scienceKey stage 2 scienceLearn about Forces
When two forces acting on an object are equal in size but act in opposite directions, we say that they are balanced forces.
If the forces on an object are balanced (or if there are no forces acting on it), this is what happens:
- a stationary object stays still
- a moving object continues to move at the same speed and in the same direction
Remember that an object can be moving, even if there are no forces acting on it.
We can show the forces acting on an object using a force diagram. In a force diagram, an arrow represents each force. The arrow shows:
- the size of the force (the longer the arrow, the bigger the force)
- the direction in which the force acts
The arrow should be labelled with the name of the force and its size in newtons. Textbooks often show a force with a thick coloured arrow so that it looks nice, but it is more accurate if you just use a ruler and pen or pencil to draw an arrow with a single line.
Here are some examples of situations involving balanced forces.
The forces on this hanging crate are equal in size but act in opposite directions. The weight pulls down and the tension in the rope pulls up.
Floating in water
Objects float in water when their weight is balanced by the upthrust from the water. The object will sink until the weight of the water it pushes out of the way is the same as the weight of the object.
Standing on the ground
When an object rests on a surface such as the ground, the reaction force from the ground balances its weight. The ground pushes up against the object. The reaction force is what you feel in your feet as you stand still. Without this balancing force you would sink into the ground.