After completing this lesson, you will be able to:

• explain the cause of motion;

• define the terms inertia, force, mass and momentum;

• state the three laws of motion and explain their significance;

• establish a relationship between force, mass and acceleration;

• explain friction and the factors on which it depends;

• illustrate advantages and disadvantages of friction in day to day life;

• explain how friction is increased or decreased in different situations;

• state and explain the Newton’s law of gravitation;

• distinguish between mass and weight, and express the relationship between them;

• distinguish between thrust and pressure with suitable examples;

• state the principle of Archimedes and apply it to solve problems.