Objects with masses of 293 kg and 542 kg are separated by 0.482 m. a 67.5 kg mass is placed midway between them. find the magnitude of the net gravitational force exerted by the two larger masses on the 67.5 kg mass. the value of the universal gravitational constant is 6.672 x 10⁻¹¹ n ·m² /kg² . answer in units of n.