The electric potential of a charge distribution is given by V(x, y) = 2xy - x2 - y. At which point is the electric field equal to zero?

I’ve been stuck on this for a while

When you hold a rectangular object, how does the area of the side that is resting on your hand affect the pressure and the force that the object exerts?

Amother used 150 watts of power to raise a 15 newton object in a time interval of 8.0 seconds. through what vertical distance was the object raised ?