1. A charge of +3.5 µC is placed on the x axis at x = +0.55 m, while a charge of -15 µC is placed at the origin. (a) Calculate the magnitude and direction of the net electric field on the x-axis at x = +0.8 m.

1. A charge of +3.5 µC is placed on the x axis at x = +0.55 m, while a charge of -15 µC is placed at the origin.
(a) Calculate the magnitude and direction of the net electric field on the x-axis at x = +0.8 m.
(b) Determine the magnitude and direction of the force that would act on a charge of – 8.0 µC if it was placed on the x axis at x = + 0.8 m.
A ball rolls off a platform that is 7 meters above the ground. The ball’s horizontal velocity as it leaves the platform is 4.2 m/s. (a) How much time does it take for the ball to hit the ground? (See the example box, use g = 10 m/s2.) s (b) How far from the base of the platform does the ball hit the ground? m