Question

Neil Armstrong has a weight on earth of 794 N and a mass of 81 kg. When he walked on the moon, how did his weight and mass change?

a) His weight increased, and his mass stayed the same.
b) His weight decreased, and his mass stayed the same.
c) His weight and mass both increased.
d) His weight and mass both decreased.

Answer 1

Neil Armstrong's mass remained at 81 kg on both the Earth and the Moon since mass is an unchanging property of matter. However, his weight decreased on the Moon due to the lower gravity, which is about one-sixth of Earth's gravity.

Step-by-step explanation:

When Neil Armstrong walked on the Moon, his mass remained the same, but his weight decreased. Mass is an intrinsic property of matter and does not change with location, so his mass stayed at 81 kg both on Earth and on the Moon. However, weight is the force exerted by gravity on an object and varies depending on the gravitational acceleration of the celestial body. The gravitational acceleration on the Moon is only about 1.67 m/s², which is much less than on Earth which is 9.80 m/s². Therefore, on the Moon, Neil Armstrong's weight would have been significantly less than his weight on Earth.

Accordingly, the correct answer to the student's question is: b) His weight decreased, and his mass stayed the same.