an imaginary dense star Z has 1/5 the radius of earth, but 1000 times earth's mass. How much would a masss weighing 1.0 N on earth weigh on Star z

Answer 1

The surface acceleration of gravity is proportional to M/R^2.

On the star surface, g will be higher by a factor 1000/(1/5)^2 = 25000.

So, multiply the weight on Earth by that factor