Acceleration with change in direction

[Mavlax]

Homework Statement

Calculate the average acceleration of the tip of the second hand from the moment it hits the 12 to the moment it hits the 3 position. The radius is 5 cm. Its a clock by the way.
I've been at it for over an hour and am beginning to susspect my textbook is wrong.

Homework Equations

a= v2 - v1 / t

The Attempt at a Solution

I got 0.0047 m/s squard.
The textbook says its 4.9 x 10 to the power of negative four [S 45 W]. So 0.00049 m/s squard.

 

[shaurya]

Can you give the detailed explanation?...by the way did you do the conversion right i.e. 5cm=0.05m

 

[The legend]

i solved it and found the text is right ... you haven't done the conversion.
5cm = 0.05m

 

[shaurya]

Yes the answer is correct as per the textbook!