## Question

A stone, tied to the end of a string of length 50 cm, is whirled in a horizontal circle with a constant speed. If the stone makes 40 revolutions in 20 s, what is the speed of the stone along the circle?

### Solution

Given *R* = 50 cm = 0.5 m. Now time period Therefore . Speed (*v*) of the stone along the circle is

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