Identical charges A, B, C, and D, each with a charge of magnitude 1.5 micro Coulomb, are situated at the corners of a square whose sides are 21 cm long. Two diagonally opposite charges are positive, the other two negative.
Calculate the net force acting on each of the four spheres.

Which statements identify what astronomers currently know and think will happen with our universe? check all that apply. the big bang produced dark energy, which accounts for some of the energy needed to expand the universe. the vastness of space may contain a type of matter known as "dark matter." the universe is currently shrinking at a rapid rate. the universe is currently expanding at an accelerating rate. the big bang theory explains all the energy and matter discovered by scientists.