Abrick of mass 2.3 kg is lifted to a height of 1.9 m. how much gravitational potential energy is added to the brick? acceleration due to gravity is g = 9.8 m/s2.

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.)