What is the electric potential (relative to infinity) due to these charges at the center of this square

Rank the torques on the five doors shown in the figure above from least to greatest. note that the magnitude of all the forces is the same

Explain what happens at the saturation point when adding salt to water at room temperature.

Astone is thrown with a speed v0 and returns to earth, as the drawing shows. ignore friction and air resistance, and consider the initial and final locations of the stone. which one of the following correctly describes the change δpe in the gravitational potential energy and the change δke in the kinetic energy of the stone as it moves from its initial to its final location? options a.δpe = 0 j and δke = 0 j b.δpe is positive and δke is negative c.δpe = 0 j and δke is positive d.δpe is negative and δke is positive e.δpe = 0 j and δke is negative