An object weighs 100 newtons on earth. What is its weight on the moon?

20 N

Explanation:

Consider that earth's acceleration due to gravity is approximately 9.81 m/s^2. Also consider that the moon's acceleration due to gravity is about 1.62 m/s^2. Using these two values, we can easily find the weight of the object on the moon, given that the object weighs 100 N, and that F = ma.

First, let's break it up.

100/9.81 =

10.193679918450561 kg

10.193679918450561*1.62 =

16.513761467889908 N

≈ 20 N (with one significant digit, since that is the least amount of sig figs in the problem)