Question

A stone tied to one end of string $80cm$ long is whirled in a horizontal circle with a constant speed. A stone makes $25$ revolutions in $14sec$, the magnitude of acceleration of stone is

• A. $850cm/s^2$
• B. $100.7cm/s^2$
• C. $720cm/s^2$
• D. $650cm/s^2$

Answer 1

Answer: (B)

$100.7cm/s^2$

Centripetal acceleration,

$=r{w}^2$

$=r\times (2\pi f{)}^2$

$=0.8\times {(2\times \frac{22}{7}\times \frac{25}{14})}^2$

$=0.8\times {\left(\frac{550}{49}\right)}^2$

$=0.8\times \frac{302500}{2401}$

$=100.79cm/s^2$