Calculating the Velocity of a Fireman Sliding Down a Pole

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Homework Statement



A fireman of mass (m) slides a distance (d) down a pole. He starts from rest. He moves as fast at the bottom as if he had stepped off a platform a distance h) <(or equal to) (d) above the ground and descended with negligible air resistance.

In terms of (g), (h), and (d), what is the speed of the fireman when he is a distance (y) above the bottom of the pole?

Homework Equations



KE=1/2mv^2
PE=mgh

The Attempt at a Solution



I tried setting KE=PE and making height equal to: h/d-y, but that didn't work. Any ideas? Thanks.
 
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Total Energy remains constant so:

KE_Top + PE_Top = KE_y + PE_y
0 + mgh = 0.5mv^2 + mgy
mg(h-y)=0.5mv^2
2g(h-y)=v^2
v=(2g(h-y)^0.5

y=d-h
Therefore
v=(2g(h-(d-h))^0.5
=(2g(2h-d))^0.5

Is my best bet.