Calculating Escape Velocity and Energy Requirements for Ceres

[x-mather]

The asteroid Ceres has mass of 7 times 10 to the power of 20 kg and radius of 550000 m.

a)What is the gravitational field strength at the surface of Ceres? DONE 0.15 N kg to the power of -1

b)What is the gravitational potential at the surface of Ceres?DONE 85 kilo J kg to the power of -1

c)What is the minimum escape velocity from the surface?DONE 410 m s to the power of -1

d)What is the minimum energy required to escape from Ceres? i do not know this part. Could I use a formulae of Kinetik energy? Please help me.

 

[Atran]

I'm not an expert yet. Therefore I'm not sure of my post.

I think this formula may be helpful:

v² = 2gh

You have v (= minimum escape velocity) and g (= gravitational field strength).
You can figure out h (= height),

and you already know:
E_p = mgh
E = mv² / 2

You need mass for calculating energy. Can you use 1 kg mass in the formula? I don't know...

 

[Keldon7]

The energy required is the energy it takes to go from the surface of the asteroid to infinity. So, unless I'm mistaken, you must integrate the force over that distance.

 

[x-mather]

Thank you both.
However, is someone really suru about right formulae?