To determine which quantity represents the astronaut's mass, we need to analyze how each quantity behaves on Earth and on the Moon.
1. Quantity A Analysis:
- On Earth, Quantity A is 70 units.
- On the Moon, Quantity A is also 70 units.
- This indicates that Quantity A remains constant regardless of location.
2. Quantity B Analysis:
- On Earth, Quantity B is 686 units.
- On the Moon, Quantity B is 112 units.
- This indicates that Quantity B changes depending on the location, specifically with gravitational strength.
Key Concept:
- Mass is an intrinsic property of an object and does not change regardless of location or gravitational conditions.
- Weight, on the other hand, is dependent on the gravitational force acting on the object and therefore changes with different gravity strengths.
Given these principles:
- Quantity A: Since it remains the same on both Earth and Moon, it must represent the astronaut's mass.
- Quantity B: Since it changes based on gravitational strength, it must represent the astronaut's weight.
Conclusion:
The quantity that represents the astronaut's mass is Quantity A. This is because the mass of an object remains constant regardless of location, and this matches with how Quantity A behaves.
Hence, the correct answer is:
Quantity A, because it remains the same throughout.
