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NTA Abhyas JEE Main2020PhysicsGravitationPractice

A rocket is fired with a speed u = 3 g R from the earth surface. What will be its speed at interstellar space?

Options

  1. Azero
  2. B2 g R
  3. C7 g R
  4. D3 g R

Correct answer

C. 7 g R

Step-by-step solution

From conservation of mechanical energy K . E . + P . E . s u r f a c e = K . E . + P . E . i n f i n i t y 1 2 m 3 g R 2 + - G M m R = 1 2 m   v ∞ 2 + 0 or v ∞ = 7 g R

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