Two cars X and Y are moving in the same direction with velocities of 40 m/s and 20 m/s respectively. What is relative velocity of car X

respect to car Y? If both car are travelling in opposite direction, what

will be the relative velocity?​

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