1. Laser light from Earth is received for an experiment by an Earth satellite. Is the light redshifted or blue- shifted? What happens to the light if it is re?ected back to Earth?
2. Explain why true weightlessness occurs only at the center of mass of the space station as it rotates around Earth.
3. Why does a drop of water become bulged in the space station due to Earth's gravitational ?eld? Draw the water drop showing the direction to Earth's center.
4. Devise a way for the occupants of a spaceship to know whether they are being pulled into a black hole. What can they do if they determine they are within the Schwarzschild radius?
5. Astronauts riding in the space station are said to be in "zero-free" or "micro" gravity. Explain why this is not really so. Is the net force on them zero?