Question

A stone tied to the end of 20 cm long string is whirled in a horizontal circle. If the centripetal acceleration is 9.8 ms^–2, its angular speed in radian/s is –

• A. 22/7
• B. 7
• C. 14
• D. 20

Answer 1

Answer: (B)

7

Answer 2

a_c = $\frac{v^{2}}{r}$ = w²r, w = $\sqrt{\frac{a_{c}}{r}}$