In: Physics
Having aced your introductory physics course, you are hired as a summer intern at NASA. You are sent as part of a team to explore the possibility of mining iron from a small, airless spherical asteroid with a radius of 469 km and a surface acceleration of 3.4 m/sec2.
4)How far will the 3 kg rock go if it leaves the asteroids surface with a vertical velocity of 1000 m/sec?"
(Not sure why the answer isn't 147059 m. I used vf^2 = vi^2 + 2ah. 0 = 1000^2 + 2 * -3.4 m/s * h. h = (1000^2) / (2*3.4) = 147059 m.)
5)What will the speed of the 6 kg rock be at the surface of the asteroid if it is dropped from a point 1000km above the surface of the asteroid?
(Not sure why the answer isn't 2608 m/s. I did v=sqrt(2ah) = sqrt(2*3.4*1000000).)
As the height it reaches is comparable o its radius, the gravitational acceleration is not constant throughout the whole path. As we know that gravitational force varies inversely with r^2. So we have to use energy conservation here.