Posted by James on Tuesday, June 26, 2012 at 5:50pm.
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.)

Physics  ajayb, Wednesday, June 27, 2012 at 2:01pm
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
Answer This Question
Related Questions
 Physics  Suppose a planet is discovered orbiting a distant star with 13 times ...
 Astro  Suppose you lived on a planet with the same radius as the Earth, but it ...
 Chemistry  A newly discovered giant planet has an aver age radius 12 times ...
 volume,mass,weight  if you travelled to a planet that had twice the force of ...
 physics help 3!! **  Based on the following data about planet X (which orbits ...
 Physics  A simple pendulum has a period T on the surface of planet Earth. When ...
 astronomy  6. Suppose that you travel to a planet that has 4 times the Earthâ€™s ...
 Astronomy  Suppose that you travel to a planet that has 4 times the Earth's ...
 college physics  A new planet has been discovered that has a mass onetenth ...
 College Physics  Suppose a planet is discovered that has the same total mass as...
More Related Questions