Question

an astronaut’s pack weighs 18.5 n when she is on earth but only 3.44 n when she is at the surface of moon. part b what is the mass of the pack on this moon? express your answer with the appropriate units.

Explanation:

Step1: Recall the formula for weight

Weight \( W = mg \), where \( m \) is mass and \( g \) is the acceleration due to gravity. On Earth, \( g_{earth} = 9.8\ m/s^2 \). First, find the mass of the pack using its weight on Earth.
Given \( W_{earth} = 18.5\ N \), from \( W = mg \), we get \( m=\frac{W_{earth}}{g_{earth}} \).
Substitute \( W_{earth} = 18.5\ N \) and \( g_{earth}=9.8\ m/s^2 \):
\( m=\frac{18.5}{9.8}\approx1.89\ kg \)

Step2: Mass is invariant

Mass of an object does not change with location (it is a scalar quantity representing the amount of matter). So the mass of the pack on the Moon is the same as its mass on Earth.

Answer:

The mass of the pack on the moon is approximately \( 1.89\ kg \) (or using more precise calculation: \( \frac{18.5}{9.8}\approx1.89\ kg \), and since mass is constant, this is also the mass on the moon).