5IEC T2 Physics 9Id Turning Forces

How can we move heavy objects?

using levers

What is a lever?

A lever is a long bar that turns around a pivot

What is it called when you push down on one side of a lever

You are applying an effort.

What is an object placed on a lever called?

The object is called a load.

What happens if the lever is longer?

It is easier to move the load.

How do most levers work?

Most levers work by changing a smaller force into a bigger one

What do levers act as if the effort distance is greater than the load distance?

Levers act as force multipliers.

What is a bottle opener?

A bottle opener is a force multiplier.

How do some other levers work?

Some other levers work by acting as distance multipliers. In this case a large effort force moves a small distance and the load moves a greater distance.

Give an example for a distance multiplier.

Our arms are distance multipliers.

What is the turning effect of a force called?

The turning effect of a force is called a moment

What does the size of the moment depend on?

The size of the moment depends on the size of the force ad the distance between the force and the pivot.

What are moments measured in?

Moments are measured in newton metres (N m)

What is the formula for the moment of a force?

The formula for the moment of a force is the product of the force and the perpendicular distance from the pivot point to the line of action of the force.

What do we call it if the clockwise and anticlockwise moments are balanced?

We say it is in equilibrium.