Your spaceship lands on an unknown planet. to determine the characteristics of this planet, you drop a 1.50 kg wrench from 5.50 m above the ground and measure that it hits the ground 0.811 s later. you also do enough surveying to determine that the circumference of the planet is 6.28×104 km . part a what is the mass of the planet, in kilograms?

The mass of the planet is

Explanation:

We have a first part of the problem, which we resolve with kinematics, knowing that

where d is given (5.50m), d₀ is zero, v₀ is zero too (as the wrench starts falling from static position), t is given (0.811s), and a is what we want to know for the second part of the problem. We clear a

Then for the second part, we use Newton's gravitational Law, where

m is the wrench mass, M is the planet mass, G is the gravity universal constant, and r is calculated from the given circumference (with the correct units) as

Finally, we have that

Therefore, replacing with the data calculated, and the known value of G, we can calculate M of the planet

measure their densities same density, same sub

a lot of it means it can be "burned" for energy and sold at one price. if it is scarce, the price will go up