How can charged object have an effect on each other without touching

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.

A-of 75 cm by cm by 17.5 cm up. of is 2 kg a , in ,if it is in , kg/?

Which is not true about oxygen-17 and oxygen-18?