A person's weight, w, on a planet of radius d is given by w= kd, k> 0. where the constant k depends on the masses of the person and the planet. Your answer is incorrect. (a) A man weighs 180 lbs on the surface of the earth. How much does he weigh on the surface of a planet whose mass is the same the earth's, but whose radius is two times as large? One-third as large? Enter the exact answers. If the planet's radius is two times as large, the man weighs i If the planet's radius is one-third as large as large, the man weighs i eTextbook and Media Hint lbs. lbs. Assistance Used 4 Your answer is incorrect. (b) What fraction of the earth's radius must an equally massive planet have if, on this planet, the weight of the man in part (a) is one ton? Your answer is incorrect. (b) What fraction of the earth's radius must an equally massive planet have if, on this planet, the weight of the man in part (a) is one ton? Enter the exact answer. The radius is eTextbook and Media times the earth's radius. Assistance Used eTextbook