2. Questions Bank
  3. 9th Class
  4. Science
  5. Gravitation and Floatation

9th Class Science Gravitation and Floatation Question Bank Gravitation Summative Objective Problems

  • question_answer
    What is the fractional change in the value of freefall acceleration g for a particle when it is lifted from the surface to an elevation h? (\[h<\,\,<R\])

    A)  \[-2\,\,\left( \frac{R}{h} \right)\]                             

    B)  \[\frac{R}{h}\]

    C)  \[\frac{h}{R}\]                                 

    D)  \[-2\left( \frac{h}{R} \right)\]

    Correct Answer: D

    Solution :

      If \[h<<R,\,\,g=\frac{GM}{{{R}^{2}}}\Rightarrow \frac{dg}{dR}=\frac{2GM}{{{R}^{3}}}\] Given, \[dR=h\,\,\therefore \frac{dg}{h}=\frac{-2GM}{{{R}^{2}}}\times \frac{1}{R}=-\frac{g}{R}\] \[\Rightarrow \frac{dg}{g}=-2\frac{h}{R}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner