Question

With what angular velocity should a 20 m long cord be rotated such that tension in it, while reaching the highest point, is zero

• A. 0.5 rad/sec
• B. 0.2 rad/sec
• C. 7.5 rad/sec
• D. 0.7 rad/sec

Answer 1

Answer: (D)

0.7 rad/sec

Answer 2

$\omega = \sqrt{\frac{g}{r}}$ $= \sqrt{\frac{10}{20}} = \sqrt{0.5} = 0.7rad/sec$