Aturntable with a radius of 8cm rotates at 45 rpm. what is the linear speed of a point on the outside rim?

Assuming the turntable is circular, its circumference is

(2 π) x (its radius) .

That's the distance covered by a point on its rim during every complete revolution.

The distance covered by the same point during 45 revolutions is

(45) x (2 π) x (radius).

So we can write . . .

Speed of the point = (45 rev/min) · (2 · π · 8 cm / rev)

Speed = (720 π)  cm/minute

Speed = 12π  cm/second

Speed = 37.7 cm/sec

Speed = 0.377 m/s

continuous conducting path for current, power supply

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