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If the angular momentum of a planet of mass m, moving around the Sun in a circular orbit is L, about the center of the Sun, its areal velocity is

  • Option 1) L/m

     

     

  • Option 2) 4L/m

     

  • Option 3) L/2m

     

  • Option 4) 2L/m

     

Answers (1)

best_answer

 

Kepler's 2nd law -

Area of velocity = \frac{dA}{dt}

\frac{dA}{dt}=\frac{1}{2}\frac{\left ( r \right )\left ( Vdt \right )}{dt}=\frac{1}{2}rV

\frac{dA}{dt}\rightarrow Areal velocity

dA\rightarrow  small area traced

- wherein

Simiar to Law of conservation of momentum

\frac{dA}{dt}= \frac{L}{2m}

L\rightarrow Angular momentum

Known  as Law of Area

 

dA = \frac{1}{2} r^{2} d\theta

\frac{dA}{dt} = \frac{1}{2} r^{2} \frac{d\theta}{dt}

\frac{dA}{dt} = \frac{1}{2} r^{2} \omega

L = mr2 \omega

\Rightarrow \frac{dA}{dt} = \frac{L}{2m}


Option 1)

\frac{L}{m}

 

Option 2)

\frac{4L}{m}

Option 3)

\frac{L}{2m}

Option 4)

\frac{2L}{m}

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