Chapter F1
by JOVITTA CHRISTOPHER PEREIRA .
1. Effects of Force
1.1. A force can change the speed of a moving object; slow it down or speed it up
1.2. A force can change the shape or size of an object
1.3. A force can start an object moving or stop a moving object
1.4. Change the direction of a moving object
2. What is a Force?
2.1. A force is simply a push or a pull
3. How do we Measure Force?
3.1. Forces are measured with force-meters. Spring balances are force meters. There are two types of spring balances – extension spring balances and compression spring balances . In an extension spring balance, the spring stretches when a force pulls on it. The greater the force, the more the spring stretches. In a compression spring balance, the spring is compressed when a force acts on it.
4. Types of Forces
4.1. Frictional Force
4.1.1. Friction is the force that opposes motion between 2 surfaces that are in contact
4.2. Gravitational Force
4.2.1. Gravity is the force of attraction that exists between objects that have mass.
4.2.2. The strength of the pull of gravity between 2 objects depends on their mass and the distance between them.
4.3. Magnetic Force
4.3.1. Magnetic force is the force of attraction and repulsion exerted by a magnet
5. What is Pressure?
5.1. Pressure is an expression of force exerted on a surface per unit area.
5.2. The unit for pressure is Pascal (Pa)
5.3. Pressure depends on force and area
6. How to Increase Pressure?
6.1. To increase pressure we must reduce the area pressure is acting on
6.2. Example
6.2.1. A sharp knife has a small contact area with the object that needs to be cut. This ensures that the pressure is higher, making it easier for the knife to slice through and cut the things.
7. How to Decrease Pressure?
7.1. To decrease pressure we increase the area the pressure is acting on
7.2. Example
7.2.1. Skis are long so that there is a larger area. With a larger area there is less pressure acting on it, so the chances of someone sinking into the snow while skiing is very low.