Question

Neil Armstrong brought back a rock from the moon. On earth

• A. The mass of the rock will change
• B. The weight of the rock will change
• C. Mass and weight will change
• D. None of the above

Hint:

Mass depends only on the matter in the rock, weight depends on the local pull of gravity.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept.
Mass is the amount of matter a body has, and it does not depend on where the body is placed. Weight is the pull of gravity on that mass, so weight equals mass multiplied by the local gravitational acceleration, and it changes from place to place.

Step 2: Apply this to the moon rock.
On the moon, gravity is about one sixth of what it is on earth, so the rock weighed far less there than it would on earth, even though it was made of exactly the same amount of matter.
When the rock is carried back to earth, the number of atoms and the amount of matter in it stays exactly the same, so its mass does not change at all.

Step 3: Why the other options fail.
Option 1 is wrong because mass never changes just by moving a body to a place with different gravity.
Option 3 is wrong for the same reason, since only weight is location dependent, not mass.
Option 4 is wrong because there is a real, correct change to report, so "none of the above" does not apply.

Final Answer:
Moving from the moon's weaker gravity to earth's stronger gravity, the same mass now experiences a bigger pull, so the weight of the rock is what changes.