1. Forces and Static Equilibrium
Principles of EngineeringTM
Lesson Statics
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Project Lead The Way, Inc.
Copyright 2007

2. Forces and Static Equilibrium

3. Newton's Laws
Sir Isaac Newton
When an object is at rest or moving with a constant velocity, it will stay at rest or moving with a constant velocity until is is subjected to an unbalanced force.

4. Newton's Laws
Sir Isaac Newton
If an unbalanced force, F, is applied to a mass, m, then the mass will experience an acceleration, a.
F = ma

5. Newton's Laws
Sir Isaac Newton
Every force of action between objects has an equal, opposite, and collinear reaction.

6. Newton's Three Laws of Motion
1. This rock is at rest. It will stay at rest unless something really big tries to force it off!

7. Newton's Three Laws of Motion
2. Right now there is no outside force acting on it. Therefore it’s acceleration is zero.

8. Newton's Three Laws of Motion
3. The only thing acting on the object here is gravity. As the rock’s weight pushes down on the mountain, the mountain is equally pushing up on the rock.

9. Static Equilibrium
Static Equilibrium is the state of an object when it is at rest or moving with a constant velocity. There may be several forces acting on the object. If they are canceling each other out and the object is not accelerating, then it is in a state of static equilibrium.

10. Static Equilibrium
The forces here are canceling each other out. It is in a state of static equilibrium.