Ascale contains a spring with a spring constant of 291 n/m. placing a mass on the scale causes the spring to be compressed by 2.89 cm. calculate the elastic potential energy stored in the spring.

Need in all of themmm only answer if you know plsssss

Starting with only the balmer series light (visible light), how could we ensure that the solar panels generate a current that mark can use for his power station? a)by gradually increasing the brightness (amount) of light that we shine on it. b)by gradually increasing the frequency of the light we shine on it. c)by gradually increasing the wavelength of the light that we shine on it.

Could someone me find the answer to this problem.