What could be used to make necessary measurements to find static friction?

Which accounts for an increase in the temperature of a gas that is kept a constant volume

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

By what primary heat transfer mechanism does the sun warm the earth?