Question

Two planets A and B have the same material density. If the radius of A is twice that of B, then the ratio of the escape velocity vA/vB is

• A. 2
• B. √(2)
• C. 1/√(2)
• D. 1/2

Hint:

For same density planets, escape velocity is directly proportional to radius.

Answer 1

The Correct Option is A

Step 1: Escape velocity: vₑ = √((2GM)/(R))
Step 2: For same density, M R³.
Step 3: vₑ R (vA)/(vB) = (2R)/(R) = 2