A 6.0 kg rock rides from Earth to the Moon. On Earth it weighs 58.8 N. On the Moon it weighs 9.6 N.
The rock lost no matter on the trip. So why is its weight smaller there, while its mass is still 6.0 kg?
Take the two quantities one at a time.
Mass measures the quantity of matter. The rock holds the same matter on the Moon as on Earth. So its mass is 6.0 kg in both places.
Weight is different in kind. Weight is a force: the gravitational force, w = mg.
The m in that equation did not change on the trip. The g did.
Near Earth's surface, g = 9.8 N/kg, so the rock's weight there is 6.0 × 9.8 = 58.8 N.
On the Moon, g = 1.6 N/kg, so the rock's weight there is 6.0 × 1.6 = 9.6 N.
The Moon value is about a sixth of the Earth value. And the Moon's g is about a sixth of Earth's. The weight simply tracks g.
A rover is sent from Earth to Mars, where g is smaller. What happens to the rover's mass and its weight?
Where g is weaker, every weight is smaller. Where g is stronger, every weight is bigger.
Mass does neither, because the quantity of matter does not depend on g.
A space probe's weight on the Moon is smaller than its weight on Earth. Which statement gives the reason?
Hollis says: 'If astronauts carry a 2.0 kg wrench to the Moon, its mass there is still 2.0 kg.' Is Hollis correct?
A 20 kg supply case is flown from Earth to Mars, where g = 3.7 N/kg. Take g = 9.8 N/kg on Earth. What happens to its mass and its weight?
Mass is the quantity of matter. No matter was added or removed, so the mass stays 20 kg.
Weight is the gravitational force, w = mg, and Mars has a smaller g than Earth.
On Earth: w = 20 × 9.8 = 196. On Mars: w = 20 × 3.7 = 74.
The mass is unchanged at 20 kg. The weight falls from 196 N on Earth to 74 N on Mars.
The same 20 kg case drifts in deep space, far from any planet, where g is close to zero. What are its mass and weight there?
Mass: still 20 kg. The matter is all still there.
Weight: w = mg with g close to zero, so the weight is close to zero.
Mass 20 kg; weight close to 0 N.
A 3.5 kg camera drifts far from any planet or moon, where g is close to zero. Which statement is correct?
A lander settles on a planet whose g is stronger than Earth's. Compared with Earth, what is true of the lander there?
A 10 kg crate is carried from Earth to the Moon. Its mass there is still 10 kg. Which statement gives the reason?