# Unit: Forces and motion

## Lessons:

14 lessons

### What are Forces?

In this lesson we are introduced to forces. We learn about contact and non-contact forces, and the unit of force.

### Representing Forces

In this lesson we introduce balanced forces as forces of the same size in opposite directions. We also practice drawing free body diagrams.

### Resultant forces

In this lesson we learn what a resultant force is and how balanced or unbalanced force affect the motion of an object.

### Gravity

In this lesson we learn what gravity is, the difference between mass and weight, and how we can investigate mass and weight on earth.

### Weight

In this lesson we will use an equation to calculate weight on different planets and explain why weight changes on different planets. We will also use the equation to calculate mass and gravitational field strength.

### Avicenna and the story of inertia

In this lesson we will learn about the scientist Avicenna, and how the theories of motion have developed.

### Pressure

In this lesson we will learn what pressure is, calculate pressure from an equation and apply this to everyday situations.

### Investigating Speed

In this lesson we will investigate how the area of a parachute affects the speed it will drop at. We will formulate a hypothesis, carry out the investigation and describe the pattern.

### Factors that affect speed

In this lesson we will discuss the effect of frictional forces on speed and how design features can reduce these forces.

### Calculating speed using an equation

In this lesson we will use an equation to calculate the speed and learn about relative speed.

### Distance: Time graphs

In this lesson we will use a distance-time graph to describe a journey, and draw a distance-time graph for a given journey.

### Calculating speed using distance time graphs

In this lesson we will use the gradient of the distance time graph to calculate speed.

### Revision (Part 1)

In this lesson we will revisit key forces content such as resultant force, gravity and weight.

### Revision (Part 2)

In this lesson we will revisit key content such as pressure, calculating speed and distance-time graphs.