## anonymous one year ago Help please. I don't know how to setup the equation to this question an ideal spring is suspended from the ceiling. a mass m=4kg is attached to the spring stretching it a distance of 20cm. a) find the spring constant k of the spring b) how much work must be done to stretch the spring an additional 25cm

|dw:1436800114050:dw| the mass is in equilibrium, so the net force acting on it must be zero. the two forces applied on the mass are, weight ($$W=mg$$) and spring force $$F_s=k.\Delta x$$, so we can write: $\sum F = F_s-W=0$ and solve that to get the spring constant $$k$$. I called the spring stretch $$\Delta x$$ here.