Question

the minute hand of a clock is 7cm long. What is the distance and displacement of the minute hand from 9 :00a.m. to 9:30a.m.? Also calculate the speed of the motion of minute hand

Answer 1

As here given, the minute hand of a clock is 7cm long so, we can take is as the radius of the circle i.e clock

we know that if a object covers half of the circle i.e from 9:00am to 9:30am then the shortest distance or displacement will be 2r(2*radius) so, the displacement will be 2r = 2* 7 = 14cm

the distance covered by the minute hand of the clock in this case will be half of the circumfrence of the circle or

πr = 22/7 * 7 = 22 cm