A kg block compresses a spring by cm. Assume a spring constant of Nm. What is the velocity of the block?

You didn't give me any values, but I can give you a formula that will answer your question. The force exerted by a spring is given as F = -KX, where K is the spring constant and x is the distance the spring is compressed or stretched. When the spring is compressed fully, it has a force F. When the spring is at equilibrium(aka not stretched), it has a force of zero. We can average these to say that the Average force of a spring is F = 1/2 -KX. We can now substitute the -1/2 KX into the equation F = ma. This yeilds -1/2 KX = ma. Solve for acceleration, we get (-1/2 KX)/m = a. Multiply this quantity by the amount of time the spring pushed on the object, and you have your velocity. Hope this helps whoever asked. --An AP Physics Student Bored in Study Hall