A remote-controlled plane has a mass of 0.386 kg and flies in a circle with a radius of 75 m. The centripetal force on the plane is 4.0 N.

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.

Answerthe distance between the two ends of the galaxy is 150,000 light years;

Igot 56.55 as the anwer 

The answer is n = 2  and    n = 3