A man whirls a stone round his head on the end of a string 2 m long. Can the string be in a horizontal plane ? If the stone has a mass of 200g and the string will break if the tension exceeds 4 Newton, what is the smallest angle the string can make with the horizontal ? What is then the speed of the stone ?
Take g = 10m/s^2
Please see the attached figure. Open it using winzip.
The vertical component of the tension supports the weight of the stone and the horizontal component is the centripetal force required to keep it in a circle.
From figure, we can write,
T cos A = mg ...
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