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AP EAMCET · PHYSICS · Gravitation

A rocket is launched straight up from the surface of the earth. When its altitude is \(\frac{1}{3}\) of the radius of the earth, its fuel runs out and therefore it coasts. If the rocket has to escape from the gravitational pull of the earth, the minimum velocity with which it should coast is (Escape velocity on the surface of the earth is \(11.2 \mathrm{kms}^{-1}\).)

  1. A \(11.2 \mathrm{kms}^{-1}\)
  2. B \(10.7 \mathrm{kms}^{-1}\)
  3. C \(9.7 \mathrm{kms}^{-1}\)
  4. D \(8.7 \mathrm{kms}^{-1}\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(9.7 \mathrm{kms}^{-1}\)

Step-by-step Solution

Detailed explanation

Given, escape velocity on the surface of the earth. \(v_e=\sqrt{2 g R_e}=11.2 \mathrm{~km} / \mathrm{s}\)...(i) where, \(R\) is the radius of earth. Height of the rocket from the surface of earth, \(h=\frac{R_e}{3}\). If the rocket has to escape from the gravitational pull of…