# The length of a seconds hand in a watch is 1 cm. Magnitude of change in velocity of its tip in 15 sec is?

##
A: 0 cm/sec

B: #pi/60sqrt2#

C: #pi/30#

D: #pisqrt2/30#

The answer is D for your reference

A: 0 cm/sec

B:

C:

D:

The answer is D for your reference

##### 1 Answer

#### Explanation:

The velocity of the tip is tangent to the circular arc traced out by the seconds hand. Therefore In 15 seconds, the tangential velocity of the tip has changed direction 90 degrees or

At t=0,

i.e.., @ 12 o'clock, tip velocity is in horizontal direction facing East

15 seconds later,

i.e., @ 3 o'clock, tip velocty is in vertical direction facing East