What is a force?

A force is a push, a   or a pull or a twist.  A force can change the   Shape,   size or   motion of an object. For example, when a racquet strikes a tennis ball, it can cause the ball to change   motion and   size it can temporarily change the   force of the ball too.

Define the term force as a push, pull, twist or turn.

Push- A force on someone or something in order to move them away from oneself.

Pull- A force on someone or something so as to cause movement towards one self.

Twist- To bend, curl or distort a shape.

Turn- To move in a circular direction wholly or partly around an axis or a point.

Define the terms ‘balanced forces’ and ‘unbalanced forces’.

Balanced forces- Forces are balanced when they are pushing or pulling an object in one direction are the same size as the forces acting in the opposite direction.

Unbalanced forces- The tension that is pulling a force by a string, cable, chain, or similar solid object on another object.

Distinguish between contact and non-contact (forces acting at a distance) forces.

Non-contact force- A non-contact force is a force applied to an object by another body that is not in direct contact with it.  Requires two forces to touch.  Two examples of this force buoyancy and tensional force.

Contact force- A contact force is a force that acts at the point of contact between two objects that are not touching.  Two examples of contact forces include Gravitational force and a magnetic force.

Distinguish between mass and weight in terms of what they are a measure of and how they are measured and applied to different contextual situations.

Mass- A large body of matter with no definite shape and it is measured in kilograms.

Weight- The weight of an object is usually taken to be a force on the object due to gravity.  Weight is measured in kilograms (kg) or grams (g).

List general properties of magnets.

·         A magnet has two opposite poles.

·         Two similar poles repel each other.

·         The two poles are invisible.

Define the term ‘field’ in describing forces acting at a distance.

Identify everyday situations in which magnets, electromagnets and magnetic strips are used.

Magnets: They can be used for fridges, televisions, music players and videotapes

Electromagnets: They can be used for CD players, heads on hard drives and automatic doors in a grocery store.

Magnetic strips: They can be used on invitations, whiteboards and to seal boxes.

Describe frictional force as a contact force that opposes motion.

A friction force is the force exerted by a surface as an object moves across it or makes an effort to move across it.