Question

The second's hand of a watch is 2 cm long. The
speed of the tip of this hand is
(a) 0.21 cm/s (b) 2.1 cm/s
(c) 21.0 cm/s (d) none of these​

Answer 1

Answer:

(a)0.21cm/s

Explanation:

time taken to complete one rotation=60 sec

distance moved by second hand =2πR=2π×2=12.566

speed=d/t=12.566/60=0.2094 cm/s

therefore answer is (a)