Question

The minute hand of a clock is 10 cm long. Find the area on the face of the clock described by the minute hand between 9 A.M. and 9.35 A.M.
[ 4 MARKS ]

Answer 1

Fig: 1 Mark
Concept: 1 Mark
Solution: 2 Marks





Angle described by the minute hand in one minute $=6^{\circ }$

So, angle described by the minute hand in 35 minutes $=(6\times 35{)}^{\circ }={210}^{\circ }$

$\therefore$ Area swept by the minute hand in 35 minutes

= Area of a sector of angle ${210}^{\circ }$ in a circle of radius 10 cm

$=[\frac{210}{360}\times \frac{22}{7}\times (10{)}^2]c{m}^2=\mathrm{183.3.}c{m}^2$.