- #1

sachin

- 60

- 7

- Homework Statement
- the question says "There are two Planets, each with the same surface gravity, but Planet 1 has a greater radius and is less massive then Planet 2. Which of these planets has a greater escape velocity? "

- Relevant Equations
- __ GMm/R + 1/2 m v2 = 0, so v escape = root 2GM/R, which is not directly dependent on g, as g = GM/R2

the question says "There are two Planets, each with the same surface gravity, but Planet 1 has a greater radius and is less massive then Planet 2. Which of these planets has a greater escape velocity? "

(A) Planet 1

(B) Planet 2

(C) Both have the same escape velocity because surface gravity is equal

(D) Not enough information is given

we have,

__ GMm/R + 1/2 m v2 = 0, so v escape = root 2GM/R, which is not directly dependent on g, as g = GM/R2,

my concern is probably the question given in ap physics worksheet in the link given below is needing correction as if mass of the planet M is less and also it has more radius than the other planet, it can never have the same surface gravity which is given by g = GM/R2,

http://content.njctl.org/courses/sc...-gravitation-multiple-choice-2-2015-12-06.pdf

the answer given in the sheet is option is option B i.e Planet 2,

how is it possible,

thanks.

(A) Planet 1

(B) Planet 2

(C) Both have the same escape velocity because surface gravity is equal

(D) Not enough information is given

we have,

__ GMm/R + 1/2 m v2 = 0, so v escape = root 2GM/R, which is not directly dependent on g, as g = GM/R2,

my concern is probably the question given in ap physics worksheet in the link given below is needing correction as if mass of the planet M is less and also it has more radius than the other planet, it can never have the same surface gravity which is given by g = GM/R2,

http://content.njctl.org/courses/sc...-gravitation-multiple-choice-2-2015-12-06.pdf

the answer given in the sheet is option is option B i.e Planet 2,

how is it possible,

thanks.