A thin 10 kg plate rests on a smooth horizontal table. In the center of the plate, light springs with a stiffness of 100 N / m

A thin 10 kg plate rests on a smooth horizontal table. In the center of the plate, light springs with a stiffness of 100 N / m are attached. What work needs to be done to lift the plate to a height of 1 meter on the spring?

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Stretch the spring
x = F / k = m * g / k = 10 * 10/100 = 1m
Spring extension work:
A1 = k * x² / 2 = 100 * 1² / 2 = 50 J
Work to lift the plate:
A2 = m * g * h = 10 * 10 * 1 = 100 J
General work:
A = A1 + A2 = 50 + 100 = 150 J