Assertion : Generally the path of a projectile from the earth is parabolic but it is elliptical for projectiles going to very great height.
Reason : Up to ordinary height the projectile moves under a uniform gravitational force, but for great heights, projectile moves under a variable force.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Answer

A

Explanation

Upto ordinary heights the change in the distance of a projectile from the centre of the earth is negligible compared to the radius of the earth. Hence projectile moves under a nearly uniform gravitational force and its path is parabolic. But for projectiles going to great heights, the gravitational force decreases in inverse poroportion to the square of the distance of the projectile from the centre of the earth. Under such a variable force the path of projectile is elliptical.