Three point charges are located on a circular arc as shown in the figure. (a) What is the total
electric field at P, the center of the arc? (b) Find
the electric force that would be exerted on a
25.00-nC point charge placed at P.

To practice problem-solving strategy 10.1 for energy conservation problems. a sled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slides a distance d1 down the slope and then covers the distance d2 along the horizontal terrain before stopping. find the coefficient of kinetic friction μk between the sled and the ground, assuming that it is constant throughout the trip.