Using the si system of units, show that eq. 1-2 is a dimensionally homogeneous equation which gives f in newtons determine to three significant figures the gravitational force acting between two spheres that are touching each other. the mass of each sphere is 200 kg and the radius is 300 mm. m1m2 (1-2) where f force of gravitation between the two particles g universal constant of gravitation; according to experimental evidence, g 66.73(10-12) m3/(kg s') m1, m2 mass of each of the two particles r distance between the two particles