Question

A 100-kilogram astronaut travels to the moon and steps onto a bathroom scale. The scale reads 16.7 kilograms.Which statement best describes the reason for this observation?

A. The scale was designed to use the person's weight on the moon to tell him his mass.
B. The scale was designed to use the person's weight on Earth to tell him his mass.
C. The scale was designed to use the person's mass on Earth to tell him his weight.
D. The scale was designed to use the person's mass on the moon to tell him his weight.

Answer 1

The astronaut's scale reads 16.7 kilograms on the moon because the scale, which measures weight, is calibrated for Earth's gravity and displays a lower value due to the moon's weaker gravity. The astronaut's mass is unchanged, but the weight is less on the moon.

Step-by-step explanation:

The reason for the astronaut's bathroom scale reading 16.7 kilograms on the moon is due to the weaker gravitational force on the moon compared to Earth. Bathroom scales measure weight but are calibrated to indicate mass by assuming the acceleration due to gravity is Earth's 9.80 m/s². However, the moon's gravity is only about one-sixth of Earth's gravity. Therefore, while the astronaut's mass remains constant at 100 kilograms, their weight on the moon is much less, causing the scale to display a lower value when it is divided by the Earth-based gravitational constant used for calibration.