A car is moving at a speed of `72 km//h`. The diamter of its whells is `0.5 m`. If the wheels are stopped in `20` rotations by applying brakes, calcualte the angular retardation produced by the brakes.

A car is moving at a speed of `72 km//h`. The diamter of its whells is

1.	A car is moving at a speed of `72 km//h`. The diamter of its whells is `0.5 m`. If the wheels are stopped in `20` rotations by applying brakes, calcualte the angular retardation produced by the brakes.
Answer» Here, `u = 72 km//h = (72 xx 1000)/(60 xx 60) m//s = 20m//s` `r = 0.5//2 m = 0.25 m` `omega_(2) = 0, theta = 20 xx 2 pi radian, alpha = ?` `omega_(1) = (u)/(r ) = (20)/(0.25) = 80 rad//s` From `omega_(2)^(2) - omega_(1)^(2) = 2 alpha theta` `0 - (80)^(2) = 2 alpha (20 xx 2pi)` `alpha = - (80 xx 80)/(80pi) = - 25.5 rad//s^(2)`

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A car is moving at a speed of `72 km//h`. The diamter of its whells is `0.5 m`. If the wheels are stopped in `20` rotations by applying brakes, calcualte the angular retardation produced by the brakes.

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