Velocity as a function of length

[Tombo254]

Homework Statement

A uniform chain of length 3 metres and mass 6 kilograms is held by one end so that the other end
just touches the floor. If the chain is released, find its velocity as a function of the length of chain
still falling. How fast does the end of the chain hit the floor?

Homework Equations

The Attempt at a Solution

Does the mass of the chain even matter, or is it a distraction? This is for a calculus based physics course, but I think it can be solved using classical equations, ie: v=xt+1/2at2.

 

[tiny-tim]

Welcome to PF!

Hi Tombo254! Welcome to PF!

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Does the mass of the chain even matter, or is it a distraction?

you're right, it doesn't matter!

… I think it can be solved using classical equations, ie: v=xt+1/2at2.

mmm … that's only for constant acceleration …

i think you'd better use conservation of energy ​

 

[cupid.callin]

mmm … that's only for constant acceleration …

I'm confused ... the chain is falling under the effect of gravity, right? ... which is constant.

isnt it because the mass of chain in free fall changes continuously and thus v = u + at is not valid ?