Velocity Notes

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FrameRef_WallMoves.mov

A curveball has more than one measureable motion. How many does it have? (ignore spin)

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3 Motions
Forward,
Left (or Right),
Down

Velocity - Speed in a particular direction

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C. Velocity - speed in a particular direction

Velocity & Direction
St. Mary's H.S.

Focus on the man walking across this page.
Identify his 2 velocities. Which is the greater of the two?

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The answer depends on your coordinate system. The man is moving to the north (or up, forward, y) and the east (or across, to the right, x). Since his easterly displacement is greater, he has a greater easterly velocity

Ex) Joe drove 13 meters North East in 2 seconds

We can say that Joe has 3 velocities

V = 6.5 m/s N.E.

V = 5 m N/2 seconds =

2.5 m/s North

V = 12 m East/2seconds

= 6 m/s East

1. Velocity is always written with direction

Examples

• 5m/s east

• +5m/s

• 100 m/s downward

• -100 m/s

2. Equation:

V = ∆d/∆t

For straight line motion:

V = distance/time and direction

Acceleration