Four identical points charges (q=+10) are located on the corners of a rectangle. the dimensions of the rectangles are L=60cm and W = 15cm . Calculate the magnitude net electrostatic force exerted on the charge t the lower left hand corner by the other three charges

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.