l. The diagram to the right depicts the position of a planet orbiting a star at point X P at different moments in time. The magnitude of the acceleration of the planet is (a) the same at all points W (b) the greatest at Q (c) the greatest at S T (d) the greatest at U U (e) the greatest at W 2. The diagram to the right shows a rock on the end of a string being whirled around in a circle in the horizontal plane. The motion is viewed N from above and the stone is rotating clockwise. What are the directions associated with its instantaneous velocity and instantaneous acceleration, W E respectively? (a) south, west S (b) south, east (c) east, west (d) south, south (e) west, west 3. Astronauts on board an orbiting space station appear to be \"oating\" because (a) they are in the vacuum of space. (b) they are outside Earth's gravitational inuence (c) they are in free fall along with the space station itself (d) the force of gravity acting on them has been reduced to an insignicant level (e) they have become truly \"weightless\