- #1

toesockshoe

- 265

- 2

## Homework Statement

A mass m is dropped from rest above a relaxed spring of stiffness k a distance D. Find the position from where it was released where the mass attains its maximum velocity and find that maximum velocity

## Homework Equations

[tex]W_{net}=\Delta E[/tex]

## The Attempt at a Solution

ok... so obviously the mass is going to be at maximum velocity when it as distance D from the place of drop right? I stated that we can bascially ignore the spring in the problem because at the maximum velocty, the mass will JUST hit the spring and the spring won't have any impact or do any work on the mass.

so here is what i did;

SYSTEM: MASS and EARTH

[tex]W_{net}=\Delta E[/tex]

There is no work in this problem so,

[tex]0=\Delta GPE + \Delta KE [/tex]

[tex]0 = \frac{1}{2}mv_f^2-mgD [/tex]

[tex]\frac{1}{2}mv_f^2 = mgD [/tex]

[tex] v_f = \sqrt{2gD} [/tex]

am i missing something crucial?