# Force

Force2018-10-20T11:21:13+10:00

The last dot point for Preliminary PDHPE is force. This dot point asks you to understand how the body applies force in general, how it absorbs force and how it applies force to objects. Within this dot point, you will have to grasp Newtown’s three (3) laws of motion and how they are applied to sporting activities.

Newton’s laws of motion are:

1. Every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. That is, an object will remain in constant velocity until a force acts upon it to change the velocity.
2. The rate of change of momentum of an object is proportional to the force causing the change and occurs in the direction of the force. That is when a force acts on an object the change in the movement will be as large as the force and in the direction of the force.
3. For every action, there is an equal and opposite reaction. This means that when a force is applied to an object, the object applies the same force upon that which is applying the original force, but in the opposite direction.

These three laws all relate to force and the motion of objects. They are highly relevant for sport and the biomechanical principles of human movement.

The Preliminary PDHPE syllabus states:

• force
• how the body applies force
• how the body absorbs force
• applying force to an object.

Students learn to:

• apply principles of force to enhance performance through participation in practical workshops.

### Practice Exam Questions

Describe how the body absorbs force when catching a ball. 3 marks Describe the forces acting on the athlete in the image above. 5 marks

Explain the forces involved when two athletes come into contact with each other, with reference to Newtown’s laws. 8 marks