You sit on a rotating stool and hold barbells in both hands with your arms fully extended horizontally. You make one complete turn in 2 seconds. You then pull the barbells in close to your body. (a)...

You sit on a rotating stool and hold barbells in both hands with your arms fully extended horizontally. You make one

complete turn in 2 seconds. You then pull the barbells in close to your body.

(a) Estimate how long it now takes you to make one complete turn. Be clear and explicit about the principles you apply

and about your assumptions and approximations.

(b) About how much energy did you expend?