Mrs. Grosenheffer, whose mass is 141 kg, is doing a science demonstration in class. a) How much gravitational force does she exert on 55.0 kg Carly in the front row 1.50 m away?

b) How much gravitational force does she exert on 65.0 kg Norton in the back row 4.0 m away?

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.