Question

A 150-lbm astronaut took his bathroom scale a spring scale and a beam scale (compares masses) to the oon where the local gravity is g5.48 fus. Determine how much he will weigh (a) on the spring scale and (b) on the beam scale.

Answer 1

Answer:

a) 25.54 lb

b) No change

Explanation:

m = Mass of astronaut = 150 lbm

$g_e=\text{acceleration due to gravity on earth}=32.18\ ft/s^2\\ g_m=\text{acceleration due to gravity on moon}=5.48\ ft/s^2$

Weight of astronaut on earth = Mass × acceleration due to gravity on earth

= 150×32.18

= 4827 lbf

Weight of astronaut on moon = Mass × acceleration due to gravity on moon

= 150×5.48

= 822 lbf

a) On earth the mass in the spring scale shows 150 lbm because it is calibrated according to the acceleration due to gravity on earth. So, the weight of the astronaut shown on moon will be

Weight of astronaut on moon/acceleration due to gravity on earth

= 25.54 lb

b) Beam scale shows weight by comparing masses so there will be no change displayed on the beam scale.