PHYSICS PAPER 2

a) Whats the difference between scalar and vector quantities? b) what does a vector quantity represent?

Scalar quantities → magnitude only (speed,distance,mass,temp,time etc)

Vector quantities → magnitude and direction (force,velocity,displacement,acceleration,momentum etc)

Vector quantity is represented by an arrow. The length shows the magnitude and the direction shows the direction of the quantity.

What is a force?

A force is a push or pull on a object that is caused by it interacting with something.

what are two types of forces ?

Contact forces = objects are physically touching

Non-contact forces = objects are physically seperated.

what are some examples of the two types of forces?

contact forces → friction, air resistance, tension, normal contact force

non contact forces→ gravitational force, electrostatic force, magnetic force

What is meant by the weight of an object?

Weight is the force acting on an object due to gravity. The force of gravity is due to the gravitational field around the earth.

What is the ‘centre of mass’?

The weight of an object acting on a single point on the object. (middle of object)

What is weight measured by?

newtonmeter

What is the resultant force?

If a number of forces is acting on a single point, you can replace them with a single force (single force has the same effect). This single force is a resultant force.

How to calculate resultant force on a object?

What happens during workdone?

When a force causes an object to move through a distance, work is done on the object. The force does work to move the object and energy is transferred from one store to another.

How to convert newton metres → joules

1 joule =1 Newton metre

What happens work is done against frictional forces on a object?

Causes a rise in temperature of the object.