Final answer:
The weight of a 20 kg object would be 200 N on Earth, 20 N on the moon, and 2000 N on the weird planet.
Step-by-step explanation:
Weight is the gravitational force acting on an object, and it depends on the acceleration due to gravity. On Earth, the gravitational acceleration is 10 m/s², so a 20 kg object would have a weight of 200 N (20 kg x 10 m/s²) on Earth.
On the moon, where the acceleration due to gravity is 1.0 m/s², the weight of the same object would be only 20 N (20 kg x 1.0 m/s²). On the weird planet with g = 100 m/s², the weight of the object would be 2000 N (20 kg x 100 m/s²).