1. Effects of force
1.1. Change the speed of a moving object
1.1.1. Sub Idea 1
1.1.2. Sub Idea 2
1.2. Change the shape or size of an object
1.3. Start an object moving or stop a stationary object
1.4. Change the direction of a moving object
2. Types of Forces
2.1. Gravitational Force
2.2. Frictional Force
2.3. Magnetic Force
3. Frictional Force
3.1. About Frictional Force
3.1.1. It occurs when two moving surfaces are in contect.
3.1.2. Frictions slows down and stops a moving object
3.2. The use of Frictional Force
3.2.1. It holds a nail in a wall, but it wears away materials
3.3. Ways to reduce Friction
3.3.1. Add lubricants
3.3.1.1. Ball Bearings
3.3.1.2. Oil
3.3.1.3. Water
4. Pressure
4.1. Pressure increases when:
4.1.1. The force increases
4.1.2. The area decreases
4.2. Pressure is the force acting per unit area
4.3. About Pressure
4.3.1. Pressure = Force / Area
4.3.2. SI unit: N/m2 or Pascal (Pa)
4.3.3. Other units: N/cm2
5. Gravitational Force
5.1. About Gravitational Force
5.1.1. Its a force that pulls the objects towards the Earth.
5.1.2. The greater the force of gravity pulling an object, the heavier the object
5.2. Weight
5.2.1. As weight is a force, it is measured using a spring balance and is measured in Newtons
6. What is a force?
6.1. Forces are all around us. Everything we do needs a force. We need a force to lift up a book. We need a force to open a door.
6.2. Force is a push or pull.
6.3. Its S1 unit is Newton (N)
7. Magnetic Force
7.1. About Magnetic Force
7.1.1. A magnet can attract objects such as iron and steel
7.1.2. There are two poles: The North pole and the South pole
7.2. Poles
7.2.1. Unlike poles attract, like poles repel.