Height in conservation of energy problem

[acaulkin]

Homework Statement

A very Slippery ice cube slides in a vertical plane around the inside of a smooth, 20 cm diameter horizontal pipe. The ice cube's speed at the bottom of the circle is 3.0 m/s
Vi = 3.0 m/s
Height at top= 2(.20) = .40
Vf = ?

Homework Equations

KE(initial) + PE(initial) = KE(final) + PE(final)

The Attempt at a Solution

(1/2)mVi^2+0 =(1/2)mVf^2 + mgh
masses cancel out:
(1/2)Vi^2-gh = (1/2)Vf^2
Vi^2-2gh = Vf^2
sqrt(Vi^2-2gh) = Vf
Plugging in all my variables I get an answer of: 1.07 m/s
Answer should be: 2.3 m/s

 

[jbriggs444]

A very Slippery ice cube slides in a vertical plane around the inside of a smooth, 20 cm diameter horizontal pipe.
[...]
Height at top= 2(.20) = .40

I can see one problem.

 

[acaulkin]

I can see one problem.

Thank you very much!
Adjusting for this, I get the correct answer.

 

[TomHart]

Check your "Height at top calculation".