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hemetite
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A particle of mass 0.2kg hangs from and ideal spring. In equilibrium, the spring is stretched by amount of 0.49cm. The spring is then suspended from the ceiling of a lift and hangs motionless relative to the lift as the lift descends with a constant velocity of 2.0m/s. The lift then suddenly stops.
a) With what amplitude will the particle oscillate?
b) What is the equation of the motion for the particles?
Take the upward directions to be positive and g= 9.8ms-2
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solution for question a)
I know that at the point of the elevator stops. Vmax= 2.0m/s
at equilibirium
Fg=-kx
0.2*9.8= -(k)(0.0049)
k=-400
w=-sqrt(400/0.2)= -44.72
using v(t)= -wA sin(wt + teta)
at equilibirium teta= 0, v(t)=Vmax
2=-44.72*A sin (wt)
A= -(2/(44.72*sin(wt))
I am stuck now...suddenly my brain jammed...what is the value of the t here?
t= 0 or t= 2?
or since it is at equilibrium when at the point release. therefore
Vm= wA
Which then,
A= -(2/44.72)= 0.044722719
?
Please help...
a) With what amplitude will the particle oscillate?
b) What is the equation of the motion for the particles?
Take the upward directions to be positive and g= 9.8ms-2
--------------------------------------------------------------------------------------
solution for question a)
I know that at the point of the elevator stops. Vmax= 2.0m/s
at equilibirium
Fg=-kx
0.2*9.8= -(k)(0.0049)
k=-400
w=-sqrt(400/0.2)= -44.72
using v(t)= -wA sin(wt + teta)
at equilibirium teta= 0, v(t)=Vmax
2=-44.72*A sin (wt)
A= -(2/(44.72*sin(wt))
I am stuck now...suddenly my brain jammed...what is the value of the t here?
t= 0 or t= 2?
or since it is at equilibrium when at the point release. therefore
Vm= wA
Which then,
A= -(2/44.72)= 0.044722719
?
Please help...