FORCE

1. Type of forces

1.1. Gravitational force

1.1.1. New node

1.2. Magnetic force

1.3. Frictional force

2. Measurement of force

2.1. Extension spring balance

2.2. Compression spring balance

3. What is force ?

3.1. A force is a push or a pull

3.2. It is exerted when one thing interacts with another.

3.3. E.G. of push and pull is :Lifting Bending Stretching Twisting Squeezing

4. Effects of force

4.1. We cannot see a force but we can see the effects of it.

4.2. We can stop a object

4.3. Make an object move

4.4. Change the direction of an object

5. Frictional force

5.1. Also called friction

5.2. Occurs when two moving surfaces are in contact

5.3. Effects

5.3.1. Slows down and/or stops a moving object

5.3.2. Produces heat

5.4. useful friction

5.4.1. friction holds the nail on the wall

5.4.2. Friction between the bicycle brake and the road slows down the bicycle

5.4.3. Friction helps us walk

5.5. Harmful friction

5.5.1. Makes movement more difficult

5.5.2. Wears away materials

5.5.3. Produces heat

5.6. Reducing friction

5.6.1. Using smooth surfaces

5.6.2. New node

5.6.3. Lubrication

5.6.4. Streamlining

6. Magnetic Force

6.1. Force exerted by a magnet on a magnetic material (e.g. iron and steel) or another magnet.

6.2. Bar magnet has 2 poles: North-seeking pole (N) South-seeking pole (S)

6.3. Forces between magnets: Like poles repel: Magnets push away from one another Unlike poles attract: Magnets pull towards each other

6.4. Some E.G.

6.4.1. Compass

6.4.2. Magnetic catch

6.4.3. A magnet

7. Gravitational Force

7.1. Also called gravity Exists between any two objects

7.2. This is the force that causes all objects to be attracted to the Earth.

7.3. Example: A coconut falling from the tree A ball coming down after bring thrown skywards

7.4. Weight

7.4.1. gravitational force acting on an object

7.4.2. Measured using a spring balance in Newtons

7.4.3. The greater the force of gravity pulling an object, the greater the weight.