posted by zack on .
Rank the objects based on the strength of the gravitational force that would be felt by a spacecraft traveling at a distance of 10 AU from the center of each of the objects, from weakest to strongest.
1)red giant mass: 1Msun radius: 100Rsun
3)white dwarf mass: 1msun radius: 0.01Rsun
4)black hole mass: 1msun radius: (event horizon) approx. 3 km
Please help me rank them, I though that it would be by the radius since as radius increases , gravitational pull decreases and the mass is the same i ranked it weakest to strongest 1,2,3,4 but i think the black hole is not supposed to be strongest since its 10 AU and its only strong at the event horizon.. please help!
"as radius increases , gravitational pull decreases"
This rule applies to measurements made at the surface of objects with the same mass.
If we restrict ourselves to Newtonian mechanics, which should apply at 10 AU, and if the masses are all equal at 1M sun, the gravitational pull (on a relatively small space-ship) should be all equal, depicted by the Newton's law of universal gravitation:
that doesnt apply at 10AU.
all of the gravitational force would remain the same aka. all of them are the same because they are at the same distance 10AU
I JUST DID THIS PROBLEM AS WELL