Calculating Speed and Acceleration of Second Hand on Town Clock

[Muneerah]

Homework Statement

The speed of the tip of the minute hand on a
town clock is 0.00182 m/s.
What is the speed of the tip of the second
hand of the same length?
Answer in units of m/s.

What is the centripetal acceleration of the tip
of the second hand?
Answer in units of m/s².

Homework Equations

a_c=4pi²r/T²

The Attempt at a Solution

Ok to find the speed of the second, I multiplied by 60 and got .1092 m/s
for the acceleration I'm not given r, so I need to find r using this equation, V=2pi r/T
I was wondering what id T ? is it 60 seconds ? Thank you

 

[ideasrule]

for the acceleration I'm not given r, so I need to find r using this equation, V=2pi r/T
I was wondering what id T ? is it 60 seconds ? Thank you

V=2pi*r/T is just distance divided by time, so T has to be the time taken for the hand to make one revolution. Of course, that depends on which hand you're considering.

 

[kuruman]

You can find r by using the angular velocity ω from v = ω r. What is ω for the second hand?

 

[Muneerah]

so I found r which is 1.638m and I used 60s for T
I got .00728 for the acceleration and this isn't the right answer, please tell me what is it that I'm not doing right thanks.

 

[kuruman]

If you don't show exactly how you got these numbers for the radius and for the acceleration, we cannot tell you what you are not doing right.

 

[Muneerah]

If you don't show exactly how you got these numbers for the radius and for the acceleration, we cannot tell you what you are not doing right.

I'm sorry, but it's ok I figured out what I was doing wrong.