Forces

Combining Force Vectors

Finding the Resultant When Forces Act Together

← Force Resultants All Lessons Range of Resultants →
Do Now warm-up prompt

A girl applies a 5 N east force on a dresser. Her brother also exerts a 5 N force. Why didn't the dresser move?

When doesn't 100 + 100 = 200?

Vector Addition - The Setup

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Video Instruction

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B. Combining Force Vectors

Resultant - single vector that will have the same effect as two or more vectors

2 + 2 = 4 Right???

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Sometimes !!!!!

Not always true with vectors

Jumping figure asking a question
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Sometimes

2 + 2 = 0

1) Finding Resultants

Case I

Forces acting in same direction (Angle = 0 degrees)

Two forces acting in the same direction
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Resultant = 9 N East

Is resultant different than the one above?

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Second example of forces acting in the same direction

RULE when θ = 0°

Add Forces

Case II

Forces acting in opposite direction (Angle = 180°)

Two people pulling in opposite directions
Two forces acting in opposite directions
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Resultant = 40 N East

If θ = 180°

Subtract smaller vector from larger

Range of Resultants →