A woman has a mass of 50 kg on the moon. What is her mass on Earth?
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A
25 kg
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B
100 kg
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C
0kg
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D
50 kg
A woman’s mass remains the same (50 KG) regardless of her location, whether on the Moon or Earth.
Mass is constant and does not change with gravity.
- A) 25 kg:
- Mass is a scalar quantity and does not change with location. Mass remains constant regardless of whether a person is on the moon, Earth, or elsewhere in the universe. The weight of an object can change due to changes in gravity, but mass does not. Therefore, this is incorrect.
- B) 100 kg:
- Mass is constant and does not change between the moon and Earth. A woman’s mass of 50 kg on the moon would remain 50 kg on Earth. Gravity on Earth is stronger than on the moon, so her weight would be greater, but the mass would not change. Therefore, this is incorrect.
- C) 0 kg:
- This is incorrect because mass is not reduced to 0 kg on the moon or anywhere else. Mass is independent of the gravitational force acting on an object and remains the same regardless of the environment. The mass of an object on the moon or Earth would still be the same.
- D) 50 kg:
- The mass of an object remains constant regardless of location. In this case, a woman’s mass is 50 kg on the moon and will still be 50 kg on Earth. Only her weight will change because gravity on Earth is stronger than on the moon. Therefore, this is the correct answer.
Conclusion: The mass of the woman will remain 50 kg on both the moon and Earth, making D) 50 kg the correct answer.

Topic Flashcards
Click to FlipA man has a mass of 80 kg on Earth. What is his mass on the International Space Station, where he is weightless?
80 kg. Mass is the amount of matter in an object and is independent of gravity. Weightlessness is the absence of the force of weight, not mass. His mass remains 80 kg.
What is the fundamental difference between mass and weight?
Mass is a scalar quantity measuring the amount of matter (in kg). Weight is a force (in Newtons) caused by gravity acting on that mass (Weight = mass x gravitational acceleration).
If an object weighs 100 N on Earth and 16.6 N on the Moon, what can you conclude about its mass?
Its mass is the same in both location The weight changed because the gravitational acceleration (g) changed. The mass (m) in the equation W = m*g remained constant. You can calculate it: m = W_earth / g_earth ≈ 100 N / 10 m/s² = 10 kg.
Which instrument measures mass directly, and which measures weight?
A balance scale measures mass by comparison. A spring scale or digital scale calibrated for Earth measures weight.
A rock has a mass of 5 kg. What would be the reading on an ideal spring scale for this rock on the Moon, where gravity is 1/6th of Earth's? (Use g_earth = 10 m/s² for simplicity).
Approximately 8.33 N (or 5/6 of 10 N). First, find weight on Earth: W_earth = 5 kg * 10 m/s² = 50 N. Weight on Moon is 1/6th of that: W_moon = 50 N / 6 ≈ 8.33 N. The mass is still 5 kg.