Question

Find the speed of the second hand of a clock of length 21 cm??

Answer 1

Total length of the second hand of the clock as radius, total distance in 1 revolution
= 2πr
= 2 × 22/7 × 21
= 132 cm

Time in one revolution = 60 sec.

Speed = 132/60 = 22/10 = 2.2cm/s.

Answer 2

howdy!!

your answer is --

given,length of second hand of clock is 21 cm or 0.21 meter 

so, in 60 second it compete 1 circle

now, distance of second hand clock = 2 pie r 

                                                         = 2 x 22/7 x 0.21

                                                         = 13.2 meter

therefore, speed of second hand clock 

            = distance / time = 13.2 / 60= 0.22 m/s

hope it help you