Question
Two planets P_1 and P_2 with equal mass have radii R_1 and R_2, respectively, where R_2= R_1 2 . The escape speeds of P_1 and P_2 are v_1 and v_2, respectively. Then v_2 v_1 is :
NEET
Physics
Gravitation
2026
NEET 2026 (Re-NEET)
NEET Physics Question (2026) — Solution
Options
- A. 2
- B. 1 2
- C. 1
- D. 2
Answer
D. 2
Step-by-step solution
The escape speed of a planet of mass M and radius R is given by v = 2GM R . For planet P_1, the escape speed is v_1 = 2GM R_1 . For planet P_2, the escape speed is v_2 = 2GM R_2 . Taking the ratio of the escape speeds: v_2 v_1 = R_1 R_2 Given that R_2 = R_1 2 , substituting this into the equation gives: v_2 v_1 = R_1 R_1 2 = 2 Answer: 2
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