Forces

Equilibrium

When the Net Force on an Object Equals Zero

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Equilibrium — the state in which the resultant (net) force acting on an object equals zero

Two forces acting on an object

What is the resultant of these 2 forces?

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G. Equilibrium

resultant = 0 N

Balanced judicial scale

Ex 1

Given

What is the resultant of these 2 forces?

Two forces acting on an object
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At Equilibrium:

Fnet = 0, a = 0

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Ex 2

Given

Could the forces of 8 N, 6 N and 4 N ever produce a state of equilibrium?

8 N, 6 N and 4 N force diagram

If so, find the resultant of the forces 4 N and 6 N.

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Answer: Yes

Resultant of 4 N and 6 N = 8 N

Ex 3

Given

Could the angles of these forces ever be arranged to produce equilibrium?

4 N and 5 N force diagram at various angles
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Answer: NO

4 N and 5 N have a range of possible resultants: 1 N to 9 N

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Ex 4

Given

Could these forces ever be in equilibrium?

50 N and 15 N force diagram
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Answer: No

50 N and 15 N have a range of 65 N to 35 N

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Which Diagram Shows Equilibrium?

Given Question mark character

Which diagram represents a box in equilibrium?

Diagram 1

Diagram 1 - box with forces

Diagram 2

Diagram 2 - box with forces

June 2008 #9

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Answer explanation diagram
Answer

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