Accelerating Lift Homework: Equations of Motion

AI Thread Summary
The discussion revolves around a physics homework problem involving a block attached to a spring in an accelerating lift. The block is initially stationary when the lift accelerates at a rate Ag, leading to confusion about the correct equations of motion. The participant questions whether the acceleration A should equal -1 due to the block's stationary state at equilibrium. They propose the equation of motion as k(Xo-X) - mg = mx'', but are unsure about the correct formulation and how to solve it. The need for clarification on the equations of motion in an inertial frame is emphasized.
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Homework Statement



A light spring force const. k hands from ceiling of an accelerating lift with a block of mass m attached to its bottom end. Block is held stationary (in lift frame) with the string at its equilibrium length while the lift is accelerating at a rate Ag where A is between -1 and 1 (const.) At t=0 the block is released from rest allowing it to execute SHM. Denote X by distance of block from origin of intertial FoR and Xo its distance when the spring is at equil. length..

write down eqn of motion of block in interial FoR..

then more qs

Homework Equations





The Attempt at a Solution



Im quite confused.
So taken intertial FoR to be the ground. but if block is stationary when spring is at equilibrium length and lift accelerating at Ag then surely that means A = -1?

help? Thanks
 
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Thoughts? This is quite urgent sorry!
 
Is it k(Xo-X) - mg = mx''?
 
Actually I get (Xo-X)'' + k/m(Xo-X) = g

I know Xo'' = Ag

but how do i solve this eqn of motion?
 

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