Question

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

Answer 1

(a) When a body moves in a circular path with uniform speed (constant speed), its motion is called uniform circular motion.
Examples-
(i) Artificial satellites move in uniform circular motion around the earth.
(ii) Motion of a cyclist on a circular track.

(b) We have the following information,
Time, (T) = 60 s
Radius of circular path, (r = 0.105)
The speed of a body moving along a circular path is given by the formula:
$$\begin{gathered} v=\frac{2\pi r}{T} \\ v=\frac{2\left(22\right)(0.105)}{\left(60\right)\left(7\right)}\mathrm{m}/\mathrm{s} \\ =\left(\frac{4.62}{420}\right)\mathrm{m}/\mathrm{s} \\ =\boxed{0.01\mathrm{m}/\mathrm{s}} \end{gathered}$$