Assertion : For the planets orbiting around t | vedclass

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(A) The net torque acting on the planet orbiting the sun is zero because the gravitational force is a central force,i.e.,$	au = 0$.According to the p

Vedclass · Accepted Answer

If both $Assertion$ and $Reason$ are correct and the $Reason$ is a correct explanation of the $Assertion$.

Vedclass · Answer

(A) The net torque acting on the planet orbiting the sun is zero because the gravitational force is a central force,i.e.,$	au = 0$.According to the principle of conservation of angular momentum,$\frac{dL}{dt} = 	au$.Since $	au = 0$,the angular momentum $L$ remains constant.Thus,the $Reason$ statement is correct.For a planet,$L = mvr = 	ext{constant}$. As the distance $r$ between the sun and the planet changes (elliptical orbit),the linear speed $v$ must change to keep $L$ constant. Consequently,the kinetic energy $K.E. = \frac{1}{2}mv^2$ also changes.Similarly,$L = mr^2\omega = 	ext{constant}$. As $r$ changes,the angular speed $\omega$ must change.Therefore,the $Assertion$ statement is correct,and the $Reason$ provides a correct explanation for it.

$Assertion$ : For the planets orbiting around the sun,angular speed,linear speed and $K.E.$ change with time,but angular momentum remains constant.
$Reason$ : No torque is acting on the rotating planet. So its angular momentum is constant.

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$Assertion$ : For the planets orbiting around the sun,angular speed,linear speed and $K.E.$ change with time,but angular momentum remains constant.$Reason$ : No torque is acting on the rotating planet. So its angular momentum is constant.