Astudent uses a spring with a spring constant of 130 n/m in his projectile apparatus. when 56 j of
potential energy is required to launch the projectile to a certain height, what is the compression in the
spring?

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