I got a question. If a mass hangs motionless from a spring, what is the force exerted on the mass by the spring in terms of the spring constant, k? So I was thinking when a load of mass m is used on the spring it will stretch by a distance x, and as the extention is directly propotional to the weight the spring should obey Hooke's law. Thus mg=-kx. However the queston asks for the force exerted by the mass and I am not too sure how that is obtained. There is obvioisly no SHM, so I can;t use T=2pi sqroot m/k. any ideas as to how this is solved?