Q. A pipe open at one end only has a fundamental frequency of 251 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 13 Hz is heard. How many centimeters were cut off the end of the second pipe? The speed of sound is 343 m/s

Q. A dipole with dipole moment 1.6 {rm nCcdot m} is oriented at 45{^circ} to a 3.4 {rm MN/C} electric field. What is the magnitude of the torque on the dipole?