(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The left side of the figure shows a light (`massless') spring of length 0.300 m in its relaxed position. It is compressed to 67.0 percent of its relaxed length, and a mass M= 0.190 kg is placed on top and released from rest (shown on the right).

[URL]http://loncapa.gwu.edu/res/msu/physicslib/msuphysicslib/13_EnergyConservation/graphics/prob24_CompSpring.gif[/URL]

The mass then travels vertically and it takes 1.30 s for the mass to reach the top of its trajectory. Calculate the spring constant, in N/m. (Use g=9.81 m/s2). Assume that the time required for the spring to reach its full extension is negligible.

2. Relevant equations

Fs=-kx

Us=(1/2)kx^2

3. The attempt at a solution

first off this is the data that i use

l(relax)=.3

l(tensed)=.201

so the X for spring = .3-.201 = .099

x=.099

m=.190

V(final)=0

t=1.3

a=-9.81

k=?

i found V(initial)

vFinal=vInitial+at

vInitial = 12.753

next i found the distance

x = v(initial) + (1/2)at^2

x= 8.2979

then i put

K+U(gravity)+U(spring)=Total energy

15.45+15.466+.0049K=0

K=6308.74

and it is wrong... i'm really confused

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# Homework Help: Finding spring constant of mass

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