### Introduction

In this Section we show how the idea of integration as the limit of a sum can be used to find the centre of mass of an object such as a thin plate (like a sheet of metal). Such a plate is also known as a
**
lamina
**
. An understanding of the term
**
moment
**
is necessary and so this concept is introduced.

#### Prerequisites

- understand integration as the limit of a sum
- be able to calculate definite integrals

#### Learning Outcomes

- calculate the position of the centre of mass of a variety of simple plane shapes

#### Contents

1 The centre of mass of a collection of point masses1.1 Distribution of particles in a plane

2 Finding the centre of mass of a plane uniform lamina

2.1 Mass per unit area

3 Engineering Example 1

3.1 Suspended cable