ample 30 Figure shows two discs of same mass m They are

Last updated: 6/12/2023

ample 30 Figure shows two discs of same mass m They are rigidly attached to a spring of stillness k The system is in equilibrium From this equilibrium position the upper disc is pressed down slowly by a distance x and released Find the minimum value of x if the lower disc is just lifted off the ground m Solution Let us first find out the minimum elongation x needed to lift the lower disc from the ground The free body diagram of the lower disc at this instant will be kx m N 0 mg Now lower disc The system given in the question is in equilibrium thus for the equilibrium of upper disc initial compression x in spring is mg m k kx mg mg k mg k kx Now from this equilibrium state spring is further compressed by an amount x and released Now let us apply energy conservation from this compressed state and final state Let us take the reference for gravitation potential energy at unstretched position then 1 k x x 1 mg x x mgx kx mg mg k x