Q. Two students are on a balcony 20.0 m above the street. One student throws a ball (ball 1) vertically downward at 12.7 m/s; at the same instant, the other student throws a ball (ball 2) vertically upward at the same speed. The second ball just misses the balcony on the way down. What is the velocity of each ball as it strikes the ground?
Q. A pipe open at one end only has a fundamental frequency of 286 Hz. A second pipe, initially identical to the first pipe, is shortened by cutting off a portion of the open end. Now, when both pipes vibrate at their fundamental frequencies, a beat frequency of 15 Hz is heard. How many centimeters were cut off the end of the second pipe? The speed of sound is 343 m/s.