If this spring is compressed 0.6 m what is its spring potential energy?

How would doubling the made of an object change the objects potential energy

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e

What is the role of lenses in microscopy?