Forces Push Pull Twist

FORCES CAN…… Change the direction that objects move in This could mean an object goes from forward to backward An object could speed up or slow down Unbalanced forces make an object move in the direction of the biggest force. If all the forces are equal the object does not move Arrows can be used to show the direction and size of a force Change the shape of objects This can be permanent or temporary The force changes the way the particles in the object are organised

Types of Forces Contact Forces Some examples are: These are forces that touch the object that they are working on Some examples are: pushing a door Forces acting at a distance These are forces that we can’t always see. Some examples are: Magnetic fields

Force Meters Measures the size of a force The spring stretches at a constant rate The unit is Newtons The symbol is N 1Newton = 10 grams

Gravity is a Force The force of gravity depends on the size of the planet that your on The earth has 6 times the gravity of the moon If your mass on earth was 60kg your weight would be 600N (on the moon it would be 100N) It you want to overcome gravity (i.e. get of the ground) your force needs to be stronger than gravity in the opposite direction

Friction is a Force Friction slows objects down It opposes the force that is moving the object E.g. a helicopter is being dragged down by gravity. Friction with the air keeps the helicopter in the air longer Friction can be helpful E.g. keeping you car on the road Friction can cause damage E.g. it can wear out parts in an engine

Machines Overcome Some Forces A machine can make work easier Pulleys, wheels, ramps and levers can be used to spread the work out, this means the same forces is needed but in smaller amounts

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