Chapter 4: Turning Effects of Forces b- IGCSE Physics

Which word means the turning effect of a force?

Moment

State three way of increasing the turning effect of a force.

Greater force / push harder; push further from the pivot; push at 90 degrees to the object

What two things must be true for something to be in equilibrium?

Forces are balanced / no resultant force; turning effects (moments) are balanced / no resultant turning effect (moment)

What will happen to an object if there is a resultant turning effect on it?

it will start to rotate / it will rotate faster

Write down the equation for moment, in words.

Moment of a force = force x perpendicular distance from pivot to force

For this equation to work, what must be the angle between the force and the distance?

90 degrees

What are the units of 'moment'?

Newton metre / Nm

What is the name of the point where all of an object's mass seems to be concentrated?

Centre of mass

An object will tip over when the line of action of the weight is...

Beyond the edge of the base

What are the two ways to make an object stable (difficult to tip over)?

Low centre of mass; wide base

What is the technical name for a flat shape (eg a piece of card)?

Lamina

In this flat shape experiment, how do you know where the centre of mass is?

Centre of mass is where the lines cross

In this flat shape experiment, what is the minimum number of lines you have to draw?

2