Turning forces and centre of gravity Flashcards Preview

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Flashcards in Turning forces and centre of gravity Deck (20)
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1
Q

How is the moment calculated?

A

moment = force X distance from the fulcrum

2
Q

what is a lever?

A

A lever is a rigid body which is free to rotate about a fixed point called a fulcrum

3
Q

give an example of a fulcrum

A

eg the middle of a see saw would be called
a fulcrum

4
Q

What is a fulcrum?

A

the pivot about which a lever turns

5
Q

give three examples of levers

A

Examples of levers: Door, door handle, scissors.

6
Q

what is the moment of a force?

A

how much the force can turn an object

7
Q

what does the law of the lever state?

A

The law of the lever states that when a lever (eg metre stick) is balanced the sum of the clockwise moments equals the sum of the anticlockwise moments.

8
Q

how do we know when something is balanced?

A

when the clockwise moments = the anti-clockwise moments

9
Q

what is the centre of gravity of an object?

A

The centre of gravity of an object is the point through which all the weight of the object appears to act. ie the centre of its weight.

10
Q

give an example showing the centre of gravity

A

Eg you can balance a pen on your finger if you place your finger at the centre of gravity, if not the pen will fall)

11
Q

what are the requirements for an object to be stable under gravity?

A

The centre of gravity should be as low as possible.

The area of the base should be as large as possible.

12
Q

name the three states of equilibrium

A

stable
unstable
neutral

13
Q

how many states of equilibrium are there?

A

3

14
Q

what do we call it when an object is balanced?

A

it is in equilibrium

15
Q

what is equilibrium?

A

when something is balanced

16
Q

how do we know if an object is in stable equilibrium?

A

An object is in stable equilibrium if it does not topple easily when a small force is applied to it.

17
Q

how do we know if an object is in unstable equilibrium?

A

An object is in unstable equilibrium if it will topple easily when a small force is applied to it.

18
Q

do the experiment to find centre of gravity of irregular shaped cardboard

A

.

19
Q

how do we know when something is in neutral equilibrium?

A

if when a small force is applied to it it’s centre of gravity does not change e.g a perfect sphere rolling

20
Q

what is a plumbline?

A

a cord from which a metal weight is suspended pointing directly to the earth’s centre of gravity