Two point charges are fixed on the y axis: a negative point charge q1 = -28 µC at y1 = +0.20 m and a positive point charge q2 at y2 = +0.33 m. A third point charge q = +8.7 µC is fixed at the origin. The net electrostatic force exerted on the charge q by the other two charges has a magnitude of 20 N and points in the +y direction. Determine the magnitude of q2.

Mutt and jeff are running along a path each pushing a cart loaded with rocks. if mutt's wagon has a mass two times greater than jeff's and they want to stay together, arriving at their destination at the same time, what must happen? a) jeff should slow down so mutt can catch up. b) mutt must use half as much force to push his cart. c) mutt must use twice as much force to push his cart. d) mutt and jeff will use the same force, but mutt will take bigger steps.

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?

The energy equivalent of the rest mass of an electron is