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Form 4 Physics uniform circular motion online lessons

Definition and formula for calculating Angular acceleration

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Answer Text:
Angular acceleration
-If the angular velocity for a body changes from ‘ω1’ to ‘ω2’, in time ‘t’ then the angular acceleration, α can be expressed as; α= $(ω2 – ω1) / t$
-Units for angular acceleration are radians per second squared $(rad s^-2) or second^-2 (s^-2)$ .
-When α is constant with time, we say the body is moving with uniform angular acceleration.
Note: In uniform circular motion α is equal to zero.
-To establish the relationship between angular acceleration and linear acceleration, from the relation, v = $radius times ω$ , then dividing by ‘t’,
we get ( $v/ t$ ) = $( radius × ω) / t$ .But $v / t$ = a (linear acceleration) and $ω / t$ = α (angular acceleration). So a = radius × α.