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Title: What is the gravitational force exerted by the planet on the astronaut? Post by: michele12 on Feb 12, 2013 An astronaut lands on a planet that has 4 times the mass of earth and twice the diameter. The astronaut's mass is 80 kg. What is the gravitational force exerted by the planet on the astronaut?
Title: What is the gravitational force exerted by the planet on the astronaut? Post by: ikk260 on Feb 12, 2013 The gravitation is governed directly by mass, and inversely by the square of the distance. Since the mass is 4 times, and the distance from center of mass is 2*2 greater, the net difference is a factor of 4/4 or 1. The answer is 80 kg.
Title: Re: What is the gravitational force exerted by the planet on the astronaut? Post by: dmitriych on Feb 16, 2013 g=G*m1/r^2 where g is the gravity, G is the gravitational constant, m1 is mass of Earth, r is radius of earth. Increasing mass by a factor of 4 and diameter (or radius) will not change g.
The previous poster was correct in this regard. Only kg is not the measure of force, it's a measure of mass. The force is measured in Newtons, therefore you have to multiply the 80kg by 9.8, The answer is: 784 Newtons |