A moment is the turning effect of a force about a pivot.

True or False? Moments cause motion.

False. Moments do not cause motion, they describe the turning effects due to forces about a pivot. The resultant force causes the motion.

What does the size of a moment depend upon?

The size of a moment depends upon both the force applied and the perpendicular distance to the pivot.

Give one example of a rotation caused by the moment of a force.

Some examples of rotation caused by the moment of a force are: a child on a see-saw a spanner a door a crane using a screwdriver to open a can of paint turning a tap on and off picking up a wheelbarrow scissors

State the units for the moment of a force.

The units for the moment of a force are newton metres (Nm).

True or False? To reduce the force required to produce a moment, the distance from the pivot must be decreased.

False. To reduce the force required to produce a moment, the distance from the pivot must be increased .

True or False? The principle of moments applies to unbalanced systems .

False. The principle of moments specifically applies to balanced systems.

True or False? The principle of moments describes a system in equilibrium.

True. The principle of moments describes the equilibrium condition in a balanced system.

True or False? See-saws, beams and levers are systems that use the principle of moments.

True. See-saws, beams and levers are systems that use the principle of moments.

True or False? A light beam is a beam treated as if it has no mass.

True. A light beam is a beam that can be treated as if it has no mass.

True or False? The forces exerted by the supports on a light beam change depending on where the object is placed on a light beam.

True. The forces exerted by the supports on a light beam do change depending on where the object is placed on the beam.

Define the centre of gravity .

The centre of gravity of an object is the point at which the weight of the object can be considered to act.

True or False? The centre of gravity is always located at the geometric centre of an object.

False. The centre of gravity can be located at the geometric centre of a regularly shaped object. This is not necessarily the case for irregularly shaped objects.

What method is used to find the centre of gravity of an irregularly shaped object?

The suspension method is used to find the centre of gravity of an irregularly shaped object.

What method is used to find the centre of gravity of a regularly shaped object?

The symmetry method is used to find the centre of gravity of a regularly shaped object.

IGCSEPhysicsEdexcelFlashcards1. Forces & MotionMoments

Moments (Edexcel IGCSE Physics)

Flashcards

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FrontMoments
Define a moment.
FrontMoments
What is the equation for calculating moments?
BackMoments
The equation used for calculating a moment is $M = F \times d$
Where:
$M$ = moment, measured in newton metres (Nm)
$F$ = force, measured in newtons (N)
$d$ = perpendicular distance to the pivot, measured in metres (m)

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Cards in this collection (19)

Define a moment.
A moment is the turning effect of a force about a pivot.
True or False?
Moments cause motion.
False.
Moments do not cause motion, they describe the turning effects due to forces about a pivot. The resultant force causes the motion.
What is the equation for calculating moments?
The equation used for calculating a moment is $M = F \times d$
Where:
- $M$ = moment, measured in newton metres (Nm)
- $F$ = force, measured in newtons (N)
- $d$ = perpendicular distance to the pivot, measured in metres (m)
What does the size of a moment depend upon?
The size of a moment depends upon both the force applied and the perpendicular distance to the pivot.
True or False?
The equation for moments with respect to the perpendicular distance to the pivot is $d = \frac{F}{M}$
False.
The equation for moments with respect to the perpendicular distance to the pivot is $d = \frac{M}{F}$
Give one example of a rotation caused by the moment of a force.
Some examples of rotation caused by the moment of a force are:
- a child on a see-saw
- a spanner
- a door
- a crane
- using a screwdriver to open a can of paint
- turning a tap on and off
- picking up a wheelbarrow
- scissors
State the units for the moment of a force.
The units for the moment of a force are newton metres (Nm).
True or False?
To reduce the force required to produce a moment, the distance from the pivot must be decreased.
False.
To reduce the force required to produce a moment, the distance from the pivot must be increased.
A force of 3 N is applied at a distance of 0.5 m from the pivot, what is the moment of the force?
When a force of 3 N is applied at a distance of 0.5 m from the pivot, the moment of the force is 1.5 Nm.
- $M = F d = 3 \times 0.5 = 1.5 Nm$
True or False?
The principle of moments applies to unbalanced systems.
False.
The principle of moments specifically applies to balanced systems.
True or False?
The principle of moments describes a system in equilibrium.
True.
The principle of moments describes the equilibrium condition in a balanced system.
True or False?
See-saws, beams and levers are systems that use the principle of moments.
True.
See-saws, beams and levers are systems that use the principle of moments.
Define the principle of moments.
The principle of moments states that if an object is balanced, the total clockwise moment about a pivot is equal to the total anticlockwise moment about that pivot.
Therefore, $clockwise moment = anticlockwise moment$ .
True or False?
A light beam is a beam treated as if it has no mass.
True.
A light beam is a beam that can be treated as if it has no mass.
True or False?
The forces exerted by the supports on a light beam change depending on where the object is placed on a light beam.
True.
The forces exerted by the supports on a light beam do change depending on where the object is placed on the beam.
Define the centre of gravity.
The centre of gravity of an object is the point at which the weight of the object can be considered to act.
True or False?
The centre of gravity is always located at the geometric centre of an object.
False.
The centre of gravity can be located at the geometric centre of a regularly shaped object. This is not necessarily the case for irregularly shaped objects.
What method is used to find the centre of gravity of an irregularly shaped object?
The suspension method is used to find the centre of gravity of an irregularly shaped object.
What method is used to find the centre of gravity of a regularly shaped object?
The symmetry method is used to find the centre of gravity of a regularly shaped object.