Physics
posted by James .
Suppose a new extrasolar planet is discovered. Its mass is double the mass of the Earth, but it has the same density and spherical shape as the Earth. How would the weight of an object at the new planet's surface differ from its weight on Earth? (Let Wnew be the weight of the object at the new planet's surface and WE be the weight of the object at the surface of the Earth. Use any variable or symbol stated above as necessary.)

g(n) = G*Mn/Rn^2 & g(e)= G*Me/Re^2
Mn=d*(4/3)*pi*Rn^3 (Mn>new planet's mass)
Me=d*(4/3)*pi*Re^3 (Me> Earth's mass)
So, g(n)/g(e) = Rn/Re .....(1)
Now, Mn/Me = 2 (given)
So Rn^3/Re^3 = 2
or Rn/Re = 2^1/3 ......(2)
From (1) & (2)
g(n)/g(e)= Rn/Re = 2^1/3
So, if the mass of the object is m:
Wn/We = m*g(n)/(m*g(e))
= 2^1/3
Respond to this Question
Similar Questions

physics help 3!! **
Based on the following data about planet X (which orbits around the Sun): Planet X's distance from Sun = 3.6*1012 m Planet X's radius = 2*106 m Planet X's mass = 8.2*1022 kg a.) Find gx, the size of the acceleration due to gravity … 
Chemistry
A newly discovered giant planet has an aver age radius 12 times that of the Earth and a mass 722 times that of the Earth. Calculate the ratio of the new planet’s den sity to the Earth’s density. 
Physics
A simple pendulum has a period T on the surface of planet Earth. When taken to the surface of planet X, the same pendulum has a period 2T. a) If the radius of planet X is 1/2 the radius of Earth, what is the mass of Planet X, relative … 
Astronomy
Suppose that you travel to a planet that has 4 times the Earth's mass and 4 times the Earth's radius. Calculate how much more or less you would weigh on this planet compared to your weight on Earth. Express your answer as a factor … 
astronomy
6. Suppose that you travel to a planet that has 4 times the Earth’s mass and 4 times the Earth’s radius. Calculate how much more or less you would weigh on this planet compared to your weight on Earth. Express your answer as a … 
Physics
Suppose a planet is discovered orbiting a distant star with 13 times the mass of the Earth and 1/13 its radius. How does the escape speed on this planet compare with that of the Earth? 
volume,mass,weight
if you travelled to a planet that had twice the force of gravity of earth and you have taken a small mass that is 1kg what is the mass weight and volume of the 1kg object on the new planet compared to earth 
Astro
Suppose you lived on a planet with the same radius as the Earth, but it had a density 2.99 times Earth's density. Your weight would be different on this planet. Find how much you would weigh on this planet divided by your weight on … 
college physics
A new planet has been discovered that has a mass onetenth that of Earth and a radius that is onesixth that of Earth. Determine the free fall acceleration on the surface of this planet. Express your answer in the appropriate mks units. 
College Physics
Suppose a planet is discovered that has the same total mass as the Earth, but half its radius. Calculate the acceleration due to gravity on the surface of this planet.