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If the acceleration due to gravity of a planet is half the acceleration due to gravity of earth’s surface and radius of planet is half the radius of the earth, the mass of planet in terms of mass of earth is

  • Option 1)  Me/2 
  • Option 2) Me/4
  • Option 3) Me/6
  • Option 4) Me/8
 

Answers (1)

best_answer

 

As we learnt in 

Acceleration due to gravity (g) -

Force extended by earth on a body is gravity.

Formula:    g=\frac{GM}{R^{2}},

g=\frac{4}{3}\pi \rho \, GR

g\rightarrow gravity

\rho \rightarrow density of earth

R \rightarrow Radius of earth

 

- wherein

It's average value is 9.8\: m/s^{2}\; \; or \; \; 981cm/sec^{2}\; or\; 32feet/s^{2} on the surface of earth

 

 g=\frac{GM}{R^{2}}

g_{p}=\frac{1}{2}g_{e}   and   R_{p}=\frac{1}{2}R_{e}

\Rightarrow \frac{g_{p}}{g_{e}}=\left ( \frac{R_{e}}{R_{p}} \right )^{2}.\frac{M_{p}}{M_{e}}

\Rightarrow \frac{M_{p}}{M_{e}}=\frac{g_{p}}{g_{e}}\left ( \frac{R_{p}}{R_{e}} \right )^{2}=\frac{1}{2}.\frac{1}{4}=\frac{1}{8}

\Rightarrow M_{p}=\frac{M_e}{8}

 

 

 


Option 1)

\frac{Me}{2}

This is incorrect option

Option 2)

\frac{Me}{4}

This is incorrect option

Option 3)

\frac{Me}{6}

This is incorrect option

Option 4)

\frac{Me}{8}

This is correct option

Posted by

divya.saini

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