Two electric charges +q are separated by a distance d. Where is a third charged particle to be placed if the electrostatic force needs to be zero?

Using software, a simulation of a javelin being thrown both on earth and on the moon is created. in both cases, the velocity and angle of projection are kept the same. on earth, the javelin covers a distance y. what distance would it cover on the moon? (the moon’s gravity is about 1/6th that of earth.) a. 6y b. 6/y c. y/6 d. (y+6)2

Plss anybody know how to do this? ? i need the answers from a through d

In the sport of parasailing, a person is attached to a rope being pulled by a boat while hanging from a parachute-like sail. a rider is towed at a constant speed by a rope that is at an angle of 15 ∘ from horizontal. the tension in the rope is 1900 n. the force of the sail on the rider is 30∘ from horizontal. what is the weight of the rider? express your answer with the appropriate units.