A mass 'M' is suspended from a ceiling through a string of length 'L'. This mass moves in a circle of horizontal radius 'r' at constant speed such that it is a conical pendulum. The tension in the string will be
- A. mgL / (2\sqrt{L²-r²})
- B. mgL / \sqrt{L²}
- C. mgL / \sqrt{r²}
- D. mgL / \sqrt{L²-r²}
Answer: D. mgL / \sqrt{L²-r²}
Explanation: T cos(theta) = mg. cos(theta) = h/L = $\sqrt{L²-r²}$/L. T = mgL / $\sqrt{L²-r²}$.