The correct option is B 4.4×10−3cms,1.8×10−4cms
At 6 AM the tip of the minute hand is at 12 mark and at 6:30 AM or 6:30 PM it is 180∘ away. Thus, the straight-line distance between the initial and final positions of the tip of minute hand is equal to the diameter of the clock.
Displacement =2×R=2×4 cm=8 cm
The displacement is from 12 mark to 6 mark on the clock panel. This is also the direction of the average velocity in both the cases. Therefore,
(a) The time taken from 6 AM to 6:30 AM is 30 min=1800 s. The average velocity is
vav=DisplacementTime=81800=4.4×10−3 cms
(b) The time taken from 6 AM to 6:30 PM is 12.5 hr=45000 s. The average velocity is
vav=DisplacementTime=845000=1.8×10−4 cms