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Smartguy94
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Homework Statement
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.
Homework Equations
Fs=-kx
Us=(1/2)kx^2
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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