# Physics Chapter 3 Summary- Forces

Get Started. It's Free Physics Chapter 3 Summary- Forces ## 2. Newton's 1st Law

### 2.4. In this law, the forces are balanced

2.4.1. For example...

2.4.1.1. A rock on a table

2.4.1.1.1. The rock's weight is pushing down on the table

2.4.1.1.2. The table's reaction force pushes it back (3rd law)

### 2.5. Free-fall

2.5.1. A falling object would reach a point where Air resistance = Weight

2.5.1.1. This is called terminal velocity

2.5.1.2. Resultant Force = 0N

2.5.1.2.1. No resultant force ≠ No force

2.5.1.3. All force are balanced

## 3. Newton's 2nd Law

### 3.1. The resultant forces acting upon an object is equal to the product of the mass and the acceleration of the object.

3.1.1. New node

3.1.2. Basically, F=ma

3.1.2.1. SI unit for force: newton (N)

3.1.2.2. 1N = 1kg m s^-2

3.1.3. The direction of the force is the same as the object's acceleration

3.1.4. The direction of the free body is dependent on the resultant force

## 5. Resultant Force

### 5.1. A resultant force would cause...

5.1.1. A moving object to...

5.1.1.1. A stationary object to move

5.1.1.2. Stop

5.1.1.3. Increase speed

5.1.1.4. Decrease speed

5.1.1.5. Change direction

5.1.1.6. Deform

## 6. Friction

6.1.1. Creates Heat

6.1.1.1. Causes wear and tear

6.1.2. Wastes energy

### 6.2. Good effects

6.2.1. Prevents slip

### 6.3. Reducing friction

6.3.2. Materials with low friction resistance

6.3.3. Use lubricants

6.3.4. Use air cushion

### 6.4. Depends on

6.4.1. Material type

6.4.2. Roughness

6.5.1. 1kg = 10N