# FORCE AND PRESSURE

Get Started. It's Free
FORCE AND PRESSURE

## 3. WHAT ARE THE EFFECTS OF FORCES?

### 3.2. force can change the shape of an object

3.2.1. example: when we press a platicine,it will flatten

### 3.3. force can change the speed of an object

3.3.1. example: when we push a moving car,the speed will increase

### 3.4. force can change the direction of an object

3.4.1. when we play tennis,we hit the moving ball back to the opponent's side

### 3.5. force can start a moving object

3.5.1. example: When we spin a wheel, it will start moving

### 3.6. force can stop a moving object

3.6.1. example: If we step on a moving object,it will stop moving

## 4. HOW CAN WE MEASURE FORCE?

### 4.1. We use force meters-spring balance

4.1.1. 2 types of spring balance

4.1.1.1. extension spring balance

4.1.1.1.1. The spring stretches when a force pulls on it. The greater the force,the longer the spring stretch

4.1.1.2. compression spring balance

4.1.1.2.1. The spring get compressed when a force acts upon it.

## 5. TYPES OF FORCES

### 5.1. Frictional force

5.1.1. Frictional force is a force that is created whenever 2 surfaces move or try to move across each other. ( the resistance )

5.1.2. HOW TO REDUCE FRICTION?

5.1.2.1. Frictional force can be reduced using a range of lubricants

5.1.2.1.1. example:oil,grease

5.1.2.1.2. This is because lubricants tend to make the contact smoother thus reducing the amount of frictional force.

5.1.3. others:

5.1.3.1. In some instances, frictional force is not only undesirable but also dangerous. When 2 rough surfaces are rubbed together, heat is usually generated. If this occurs with something flammable, it could result in a fire/ explosion

5.1.3.2. New node

### 5.2. Gravitational force

5.2.1. It is NOT a force of contact

### 5.3. Gravitational force can be good or bad.

5.3.1. Good in a way that it keeps us on the ground

5.3.2. Bad is that if there is a hole well…we would fall.