Give three examples of a force causing rotation about a pivot.

A child on a see-saw , turning the handle of a spanner and a door opening and closing .

A couple is a pair of equal and opposite forces that do not act through the same point, causing an object to rotate .

A door handle is placed ______ from the hinge to create a larger moment for a given force.

A door handle is placed far away from the hinge to create a larger moment for a given force.

True or False? A moment can only be created if two forces act through the same point.

False. If two forces act on an object without passing through the same point, the object can still rotate. If the forces are equal and opposite, this is called a couple .

In what units may a moment be measured?

A moment is measured in newton metres (N m) , but may also be given in newton centimetres (N cm) if the distance is measured in centimetres.

Define the principle of moments .

The principle of moments states that if an object is balanced, the total clockwise moment about a pivot equals the total anticlockwise moment about that pivot.

What condition must a force meet, relative to the distance from the pivot, when calculating a moment?

The force must be perpendicular to the distance from the pivot.

On a horizontal beam, the forces which cause a moment are those directed ______ .

On a horizontal beam, the forces which cause a moment are those directed upwards or downwards .

True or False? A beam is balanced only when the forces acting on it are equal in size.

False. A beam is balanced when the total clockwise moment about the pivot equals the total anticlockwise moment about that pivot, not simply when the forces are equal.

A parent weighing 690 N sits 0.3 m from the pivot of a see-saw. What moment do they create?

Moment = F × d = 690 × 0.3 = 207 N m .

How does a lever make it easier to turn an object?

A lever increases the size of the turning effect ( moment ) of a force by applying it further from the pivot than the force it needs to overcome.

Name two ways to make a lever work better.

Increase the size of the force applied , and increase the distance of the force from the pivot .

Define a gear , in terms of its pivot.

A gear is a wheel with toothed edges that rotates on an axle or shaft , which acts as the pivot .

When two gears interlock, in what directions do they rotate?

One gear rotates clockwise and the other rotates anticlockwise , since their teeth move in the same direction where they meet.

Although the force is the same on two interlocking gears, the ______ is not, as it depends on the size of the gear.

Although the force is the same on two interlocking gears, the moment is not, as it depends on the size of the gear.

True or False? If a larger gear is driven by a smaller gear, the larger gear rotates faster and has a greater moment.

False. If a larger gear is driven by a smaller gear, the larger gear rotates slower but has a greater moment , as in a low gear on a bike or car.

Give two examples of levers used to amplify a force.

A bottle opener and a crowbar .

GCSEPhysicsAQAFlashcardsForcesMoments, Levers & Gears

Moments, Levers & Gears (AQA GCSE Physics): Flashcards

Exam code: 8463

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FrontMoments in Physics
Define moment.

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Cards in this collection (21)

Define moment.
A moment is the turning effect of a force about a pivot.
What is the equation for calculating the moment of a force?
$M = F \times d$
Where M is the moment (N m), F is the force (N), and d is the perpendicular distance of the force from the pivot (m).
Define a pivot.
A pivot is a fixed point about which an object can rotate.
Give three examples of a force causing rotation about a pivot.
A child on a see-saw, turning the handle of a spanner and a door opening and closing.
Define a couple.
A couple is a pair of equal and opposite forces that do not act through the same point, causing an object to rotate.
A door handle is placed ______ from the hinge to create a larger moment for a given force.
A door handle is placed far away from the hinge to create a larger moment for a given force.
True or False?
A moment can only be created if two forces act through the same point.
False.
If two forces act on an object without passing through the same point, the object can still rotate. If the forces are equal and opposite, this is called a couple.
In what units may a moment be measured?
A moment is measured in newton metres (N m), but may also be given in newton centimetres (N cm) if the distance is measured in centimetres.
Define the principle of moments.
The principle of moments states that if an object is balanced, the total clockwise moment about a pivot equals the total anticlockwise moment about that pivot.
What condition must a force meet, relative to the distance from the pivot, when calculating a moment?
The force must be perpendicular to the distance from the pivot.
On a horizontal beam, the forces which cause a moment are those directed ______.
On a horizontal beam, the forces which cause a moment are those directed upwards or downwards.
True or False?
A beam is balanced only when the forces acting on it are equal in size.
False.
A beam is balanced when the total clockwise moment about the pivot equals the total anticlockwise moment about that pivot, not simply when the forces are equal.
A parent weighing 690 N sits 0.3 m from the pivot of a see-saw. What moment do they create?
Moment = F × d = 690 × 0.3 = 207 N m.
A child weighing 140 N must balance a see-saw against a moment of 207 N m. How far from the pivot must the child sit?
d = 207 ÷ 140 = 1.48 m.
How does a lever make it easier to turn an object?
A lever increases the size of the turning effect (moment) of a force by applying it further from the pivot than the force it needs to overcome.
Name two ways to make a lever work better.
Increase the size of the force applied, and increase the distance of the force from the pivot.
Define a gear, in terms of its pivot.
A gear is a wheel with toothed edges that rotates on an axle or shaft, which acts as the pivot.
When two gears interlock, in what directions do they rotate?
One gear rotates clockwise and the other rotates anticlockwise, since their teeth move in the same direction where they meet.
Although the force is the same on two interlocking gears, the ______ is not, as it depends on the size of the gear.
Although the force is the same on two interlocking gears, the moment is not, as it depends on the size of the gear.
True or False?
If a larger gear is driven by a smaller gear, the larger gear rotates faster and has a greater moment.
False.
If a larger gear is driven by a smaller gear, the larger gear rotates slower but has a greater moment, as in a low gear on a bike or car.
Give two examples of levers used to amplify a force.
A bottle opener and a crowbar.

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