A small puck of negligible height slides without friction along a straight horizontal…

PHYSICS · Multi-part · CBSE · Physics · Work, Energy and Power · Work, Energy and Power

Problem

A small puck of negligible height slides without friction along a straight horizontal air track. The puck is connected on its left side to spring A (spring constant kA=80 N/mk_A=80\,\text{N/m}) and on its right side to spring B (spring constant kB=120 N/mk_B=120\,\text{N/m}). Both springs are attached to fixed walls, so the puck is constrained to move only along the xx-axis between the springs. The coordinate axis is chosen with origin at the system’s equilibrium position, with positive xx to the right. (a) For a puck displacement x=+0.06 mx=+0.06\,\text{m}, determine the individual forces exerted on the puck by springs A and B, specifying the direction and algebraic sign of each. (b) Repeat part (a) for a displacement x=−0.06 mx=-0.06\,\text{m}. (c) Using your qualitative results from parts (a) and (b) and appropriate numerical reasoning, construct a piecewise algebraic expression for the net spring force Fnet(x)F_{\text{net}}(x) acting on the puck for any small displacement xx about equilibrium. Be sure to indicate clearly which expression applies for x>0x>0 and which applies for x<0x<0. (d) On blank axes of your own, sketch the graph of Fnet(x)F_{\text{net}}(x) versus xx for displacements in the range −0.10 m≤x≤+0.10 m-0.10\,\text{m}\le x\le+0.10\,\text{m}. Label key points, slopes, and intercepts, and explain how the graph illustrates the restoring nature of the combined spring system.

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