I don't know how to write the equations the way I see on other posts, so you'll have to bear with me.
Basically, we solved the energy using 1/2kA^2 then set an energy equation with m in it equal to our result. however as soon as we set it up, we saw that it made no sense since the m's would...
[b]1. A block of unknown mass is attached to a spring with a spring constant of 6.5 N/m and undergoes simple harmonic motion with an amplitude of 10 cm. when the block is halfway between its equilibrium position and the end point, its speed is measured to be 30 cm/s. Find the mass of the block...