why We cannot apply the four known equations of motion in one dimension on a mass attached to a spring

Point charges q1 = 51 µc and q2 = −27 µc are placed 1.0 m apart, with q2 on the right. what is the force (in n) on a third charge q3 = 19 µc placed midway between q1 and q2? (assume the positive direction is to the right. indicate the direction with the sign of your answer.)

Which form of cell division creates the sperm and egg, resulting in half of the chromosomes as the other cells?

How do you know how many valence electrons an atom has?