Question

Some space invaders build a giant gun on the surface of their planet. After wandering the planet, they find that the planet has a radius of 8.82×10⁷m, and after a simple freefall experiment, they calculate the mean mass density to be 5850kg/m³. (a) What must the muzzle velocity for the projectile to escape the planet's gravitation when fired perpendicular to the horizon? (b) What is the speed of the projectile after it has traveled a distance of 9.65×10⁶m?

Answer 1