Resultant Forces pt2

When is work done on an object?

When a force moves an object through a distance.

What happens when a force moves an object through a distance?

Energy is transferred and work is done on the object.

What is needed to make something move?

A force and a source of energy.

What is meant by 'the force does work'?

It moves the object and transfers energy from one store to another.

What is the difference between useful and wasted energy transfer?

Useful: e.g. lifting a load; Wasted: e.g. due to friction.

What is the equation for work done?

Work done (J) = Force (N) × Distance (m), along the line of action of the force.

What are the units of work done?

Joules (J).

How much work is done when a 1 N force moves an object 1 m?

1 joule (1 J).

What causes work to be done against friction?

Moving an object across a rough surface.

What does work against friction do?

It increases the thermal energy store of the object and surroundings.

How can you calculate how much work has been done?

By using the formula: Work done = Force × Distance.

How can resultant forces be found using scale drawings?

Draw all forces tip-to-tail, then measure from start to end for the resultant force.

What tools are used in a scale diagram?

Sensible scale, ruler, and protractor to find magnitude and direction.

What is a 'bearing' in resultant force?

The angle measured clockwise from north.

In a scale diagram, what does the length of the resultant line represent?

The magnitude (size) of the resultant force.