Question: If a stone is tied to a string and whirled in a horizontal circle of radius 2 m at a speed of 4 m/s, what is the tension in the string if the mass of the stone is 1 kg?
Options:
Correct Answer: 8 N
Solution:
Centripetal force = m(v²/r) = 1(4²/2) = 8 N. Tension in the string = 8 N.