(3 points) A disk is spinning freely with angular speed 6.0 rad/s when a second identical disk, initially not spinning, is dropped on it so that their axes coincide. In a short time the two disks are co-rotating. a) Sketch the initial situation and the consequential situation. b) What is the angular speed of the new system? c) If a third such disk is dropped on the first two, find the final angular speed of the system.

1. when conducting a test on what kind of music increases the growth of plants, all of the following would fail to meet to fair test standard except (1 point) using different kinds of plants. giving some plants more water than others. exposing the plants to different types of music. using nutrient-rich soil for one and lesser soil for others. 2. engineering uses scientific thinking to solve real-world problems. (1 point) true false 3. what does it mean to test a hypothesis? (1 point) pass a quiz on other scientists’ results analyze only the results from scientific sources not make assumptions about how an experiment will turn out see if the results of an experiment are what the scientist predicted