Scientific reading and explanation
Elastic energy depends on deformation
For a spring behaving according to Hooke's law, F_s=−kx where x is displacement from its unstretched equilibrium and k is stiffness in N/m. The minus sign denotes restoring direction. The stored spring energy is U_s=½kx², nonnegative for either compression or extension. Doubling the deformation quadruples stored energy at fixed k.
Units matter twice
If k=200 N/m and spring compression is 0.20 m, stored U_s=½×200×(0.20)²=4 J. Entering 20 instead of 0.20 would mistakenly treat centimeters as meters and inflate the result by a factor of 10,000. Our sliders display centimeters but calculations convert them to meters before applying x².
A simplified release is not a full oscillator
The Spring Energy Lab models a compressed spring moving from initial deformation x_0 toward a smaller deformation x. Initially the spring carries U_0=½kx_0². The released amount ΔU=½k(x_0²−x²) becomes kinetic energy plus an explicitly selected nonmechanical transfer fraction. The model does not calculate signed velocity, contact details or complete back-and-forth oscillation.
Keep a coherent system account
For the ideal spring–object system, U_s+K is constant without energy transfers out of mechanical forms. In a more inclusive energy ledger, add thermal or other energy so the total stays constant even when mechanical energy decreases. If the moving body begins with its own kinetic energy, that initial kinetic energy must also be included; this lab assumes release from rest.