CALC Consider a spring that does not obey Hooke's law very faithfully. One end of the spring is fixed. To keep the spring stretched or compressed an amount x, a force along the x-axis with x-component Fx = kx-bx² + cx³ must be applied to the free end. Here k = 100 N/m, b = 700 N/m², and c = 12,000 N/m³. Note that x>0 when the spring is stretched and x < 0 when it is compressed. How much work must be done (a) to stretch this spring by 0.050 m from its unstretched length?

CALC Consider a spring that does not obey Hooke's law very faithfully. One end of the spring is fixed. To keep the spring stretched or compressed an amount x, a force along the x-axis with x-component Fx = kx-bx² + cx³ must be applied to the free end. Here k = 100 N/m, b = 700 N/m², and c = 12,000 N/m³. Note that x>0 when the spring is stretched and x < 0 when it is compressed. How much work must be done (a) to stretch this spring by 0.050 m from its unstretched length?