Why is the law of buoyancy considered a law?

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer

J. j. thomson’s experiment disproved the theory that an atom

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.)