1. Force
1.1. What is a force?
1.1.1. A push or pull
1.1.1.1. New node
1.1.2. SI unit is newton (N)
1.1.3. It can be measured with a force- meter such as a spring balance.
1.2. Effects of forces
1.2.1. Change the shape or size of an object
1.2.2. Start an object moving or stop a moving object
1.2.3. Speed up or slow down a moving object
1.2.4. Change the direction of a moving object
1.3. Kinds of forces
1.3.1. Gravitational force (gravity)
1.3.1.1. It pulls objects towards the Earth
1.3.1.2. The force of gravity pulling down on an object is called weight
1.3.2. Magnetic Force
1.3.2.1. It is a force of attraction produced by magnets on objects made of magnetic materials such as steel, iron, nickel and cobalt
1.3.2.2. It can attract or repel other magnets
1.3.3. Frictional Force (Friction)
1.3.3.1. Produced by two moving surfaces in contact
1.3.3.2. Opposes and slows down movement
1.3.3.3. Can be useful in our daily life such as when we are walking.
1.3.3.4. Can also be a nuisance,
1.3.3.5. Ways to reduce friction
1.3.3.5.1. Ball bearings
1.3.3.5.2. Lubricants
1.3.3.5.3. Streamlining
1.3.3.5.4. Smooth surfaces
1.3.4. Magnetic force
1.3.4.1. It is the force of attraction produced by magnets on objects made of magnetic materials like iron, steel, cobalt and nickel.
1.3.4.1.1. New node
1.3.4.2. Magnets can also attract and repel other magnets.
1.3.5. Frictional force (friction)
1.3.5.1. It is produced by two moving surfaces in contact.
1.3.5.2. It will oppose and slows down movement
1.3.5.3. It can be useful to us in our daily life. For example, it is needed for walking
1.3.5.4. It also can be harmful.as it makes movement more difficult and wears off materials.
1.3.5.5. Ways to reduce firction
1.3.5.5.1. Lubrication
1.3.5.5.2. Smooth surfaces
1.3.5.5.3. Ball bearings
2. Pressure
2.1. What is it?
2.1.1. It is the force exerted per unit area
2.2. It increases when more force is exerted or when the area is smaller
2.3. Calculating pressure
2.3.1. Pressure= Force/Area