The state of an object when there is no resultant force or moment acting on it.

The turning effect of a force, measured in newton metres (Nm).

An object will balance when the clockwise moments are equal to the anticlockwise moments.

Balancing

Physics

Newton's Third Law

Resultant forces and their effects

Moments, levers and gears

Force, mass and acceleration  (a = Δv/t)

Newton's Second Law

Terminal velocity (including graphical representation)

Stopping (and estimating stopping distances)

In the Gravity in space unit, they will build on this knowledge to learn about centripetal forces, orbital motion, stellar evolution, red shift and the big bang.

In the Energy of moving objects unit, pupils learnt how to calculate the amount of energy of objects have because they are moving, stretched or in a gravitational field; and to calculate energy transfers using knowledge of energy conservation and dissipation.

This unit explores forces, interactions, and Newton’s laws, including motion, rotation, and momentum. It covers reaction times, stopping distances, and deceleration dangers. Emphasis is on force diagrams, calculations, experiments, and evaluating methods for accuracy and safety.

Forces make things change

Physical activity and equipment requiring safe use

A moment is the turning effect of a force.

An object balances when there are no moments on it.

An object balances when there is no resultant moment on it.

Moment = force × distance normal to the force direction.

Which of the following statements describes the principle of moments?

The diagram shows a balance beam in equilibrium. There are four forces acting on it: $$F_1$$, $$F_2$$, $$W$$ and $$R$$. 
Which of the following statements are correct?

To balance the beam, mass X should be moved towards the left.

To balance the beam, mass Y should be moved towards the left.

A pupil has two masses, labelled X and Y. One of the masses is twice as heavy as the other. The pupil places the masses on a balance beam, as shown. Which of the following statements are correct?

The diagram shows a beam with three forces acting on it. Which of the following statements are correct?

The beam shown in the diagram is balanced. What is the distance $$x$$?

The beam shown in the diagram is balanced. What is the size of the force $$W$$?

Which of the following statements about moments is correct?

A force of 40 N acts at a distance of 10 m normal to a pivot. The moment produced by the force is {{}} Nm.

A moment of 50 Nm is produced by a force of 20 N. The perpendicular distance between the direction of the force and the pivot is {{}} m.

A moment of 300 Nm is produced by a force acting at a distance of 50 cm from a pivot. The magnitude of the force is {{}} N.

There are no forces acting on the object.

Which of the following statements for an object with no resultant force or moments acting on it are correct?

The diagram shows a metre rule of weight 5 N balanced on a support. Two objects, of weight 2 N each, are placed on it as shown. What is the size of the upwards force labelled $$R$$?

Exit Quiz

Which of the following statements describes the principle of moments?