Question

(a) What is meant by uniform circular motion? Give two examples of uniform circular motion.
(b) The tip of seconds' hand of a dock takes $60$ seconds to move once on the circular dial of the clock If the radius of the dial of the clock be $10.5cm$, calculate the speed of the tip of the seconds' hand of the clock. $(\text{Given}\pi =\frac{22}{7}).$

Answer 1

(a) When a body moves in a circular path with uniform speed (constant speed), its motion is called uniform circular motion. For e.g.
(i) Artificial satellites move in uniform circular motion around the earth.
(ii) Motion of a cyclist on a circular track
(b) The speed of a body moving along a circular path is given by the formula:
Given, $t=60sec$
Radius, $r=10.5cm=0.105m$
$v=\frac{2\pi r}{t}$
$v=\frac{22\pi r}{t}=\frac{2\times 22\times 0.105}{7\times 60}=\frac{4.62}{420}=0.011m/s$