Physics assignment due tomorrow morning... a few questions. 1. At a time when mining asteroids has become feasible, astronauts have connected a line between their 3500kg space tug and a 6200kg asteroid. Using their ship's engine, they pull on the asteroid with a force of 490N. Initially the tug and the asteroid are at rest, 450 m apart. How much time does it take for the ship and the asteroid to meet? This one I'm just having trouble picturing it. I don't even know what a space tug is. Are the "ship" and "space tug" synonymous? Hmmm... 2. Three uniform spheres are located at the corners of an equilateral triangle. Each side of the triangle has a length of 1.2m. Two of the spheres have a mass of 2.8kg each. The third sphere (mass unknown) is released from rest. Considering only the gravitational forces that the spheres exert on each other, what is the magnitude of the initial acceleration of the third sphere? For this one... I don't see how you can get the acceleration of the 3rd sphere without its mass. 3. There is a pulley apparatus with a 412 N block on one end, and a 908 N block on one end. It asks for the accleration and I find it. For part (b), there isn't a 908 N block, but instead, there is a hand pulling with a force of 908 N. It says "Find the accleration of the remaining block. Explain why the answers in part a and b are different. Don't know why they'd be different if both forces are 908 N... Any help is greatly appreciated. Thanks in advance.