please pakai cara ya.. deadline ini.

F = kΔx → k = mg / Δx

EP = 1/2 kΔx'
      = 1/2 (mg / Δx)Δx'²
      = (0,05 kg)(10 m/s²)(0,04 m)² / [2(0,05 m)] = 8 x 10⁻³ J