- #1
Anthonyphy2013
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Homework Statement
A vertical spring with k = 490 N/m is standing on the ground. You are holding a 5.0 kg block just above the spring, not quite touching it.
The first question asks "How far does the spring compress if you slowly lower the block to the point where you can remove your hand without disturbing it?
The answer is easy...0.109m
the part I can't figure out is the second part of the question "How far does the spring compress if you let go of the block suddenly?
What is the pan's distance from the ceiling when the spring reaches its maximum length?
Homework Equations
1/2 kx^2 = 1/2mv^2 , mgh=Fsp=-kdelta(x)
The Attempt at a Solution
1st question : mgh=Fsp=-kdelta(x)
I got wrong for that question and I use the conservation of energy equation and I got it right . My question is how I know to use the energy eqaution on the first question and use net force to use the second question