Question

Assertion :It takes more fuel for a spacecraft to travel from the earth to the Moon than for the return trip. Reason: The point of zero gravitational field intensity due to earth and the Moon is lying nearer to the Moon, i.e., in the diagram shown, for $r<r_0$, $E_g$ is towards the earth's centre and for $r>r_0$, $E_g$ is towards the Moon's centre, and at $r=r_0$, $E_g$ is zero.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

From the figure, to the left of neutral point, the net force on the spacecraft will be towards left and towards right of this point, the force will be towards right. Hence, during return trip, the gravity assists more the motion of the spacecraft than during the motion from earth to moon. Hence, less fuel is required in the return path.

Both statements are correct and the latter one is correct explanation for the former.

Answer is option A.