Question

The ratio of the angular speed of hours hand and second hand of a clock is

• A. $1:1$
• B. $1:60$
• C. $1:720$
• D. $3600:1$

Answer 1

The correct option is C $1:720$

To complete one second the arm of second moves${360}^{\circ }$

Angular speed is

$\frac{2\pi }{60}$

Hour hand completes 1 rotation ${360}^{\circ }$in

$12hrs$

Angular speed is

$\frac{2\pi }{12\times 3600}$

Therefore the ratio of angular velocity is given as

$\frac{2\pi }{60}=\frac{2\pi }{12\times 3600}$

Hence the ratio of the angular speed of hour and seconds is$1:720$