# 2.1.9 Projectile Motion

### Projectile Motion

• The trajectory of an object undergoing projectile motion consists of a vertical component and a horizontal component
• These need to be evaluated separately
• Some key terms to know, and how to calculate them, are:
• Time of flight: how long the projectile is in the air
• Maximum height attained: the height at which the projectile is momentarily at rest
• Range: the horizontal distance travelled by the projectile

How to find the time of flight, maximum height and range

• Remember: the only force acting on the projectile, after it has been released, is gravity
• There are three possible scenarios for projectile motion:
• Vertical projection
• Horizontal projection
• Projection at an angle
• Let’s consider each in turn:

#### Worked Example 1

How to calculate vertical projection (free fall)

#### Worked Example 2

How to calculate horizontal projection

#### Worked Example 3

How to calculate projection at an angle

#### Exam Tip

Make sure you don’t make these common mistakes:

• Forgetting that deceleration is negative as the object rises
• Confusing the direction of sin θ and cos θ
• Not converting units (mm, cm, km etc.) to metres

### Author: Ashika

Ashika graduated with a first-class Physics degree from Manchester University and, having worked as a software engineer, focused on Physics education, creating engaging content to help students across all levels. Now an experienced GCSE and A Level Physics and Maths tutor, Ashika helps to grow and improve our Physics resources.
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