Questions: Mass vs. Weight

Question 1

An astronaut has a mass of 80 kg. On the Moon, where g ≈ 1.6 m/s², what is the astronaut's weight?

• A. 80 N
• B. 128 N
• C. 784 N
• D. 50 kg

Answer: (B)

Weight = mass × g = 80 kg × 1.6 m/s² = 128 N. The astronaut's mass stays 80 kg, but the weight is much less than on Earth (where it would be about 784 N).

Question 2

Your mass would be different on Jupiter than on Earth.

• T. True
• F. False

Answer: False

Mass is an intrinsic property of matter — it does not change based on location. Only weight changes because gravitational acceleration differs between planets.

Question 3

What is the weight of a 5 kg object on Earth (g = 9.8 m/s²)?

Model answer: 49 N, because W = mg = 5 × 9.8 = 49 N.

Weight equals mass times gravitational acceleration. 5 kg × 9.8 m/s² = 49 newtons.