Circular Motion
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Angular Velocity
Formulas
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Meaning
"Angular velocity" is a measure of turning per time unit. It tells you the size of the angle through which something revolves in a given timespan
Banked Curves
Meaning
A banked turn (or banking turn) is a turn or change of direction in which the vehicle banks or inclines, usually towards the inside of the turn.
Example
A banked surface is one that slopes upward towards the outer edge of a curve. Banked surfaces exist at on-ramps to highways because cars have to start traveling faster to enter the highway.
Centripetal Force
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Meaning
The unbalanced force acing on an object in uniform circular motion is called Centripetal force, Fcent
Is a force pushing or pulling the object towards the center of the circle.
Formula
The unbalanced force acing on an object in uniform circular motion is called Centripetal force, Fcent
Is a force pushing or pulling the object towards the center of the circle.
Features
1. Size is constant
2. Direction is towards the centre of the circular path
Example
A motorbike and rider of total mass 100 kg travel round a roundabout of radius 8 m at a speed of 4 m/s.
.
What is the centripetal force needed to do this?
F = mv2/r = [100 x 42]/8 = 200 N.
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Formulas
Net Force
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Speed
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Acceleration
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Vertical Circular Motion
Meaning
A body revolves in a vertical circle
such that its motion at different points
is different then the motion of the body
is said to be vertical circular motion.
Examples
Common examples include:
roller coasters
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Wheels
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Centripetal Acceleration
Features
1. Size is constant
2. Direction is towards the centre of the circular path
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Formula
CENTRIPETAL ACCELERATION = v2/r
Meaning
We call the acceleration of an object moving in uniform circular motion—resulting from a net external force—the centripetal acceleration.
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Example
A stone is whirled round on the end of a 1.5 m long piece of string. If the acceleration of the stone is 3g (30 m/s2) calculate the speed at which the stone is moving.
Use: a = v2/r so v2 = ar = 30x1.5 = 45 and so v = [45]1/2 = 6.7 m/s
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