Q1. A wire of mass 1 g and length 58 cm is stretched with a tension of 480 N. it is then placed near the open end of the tube and stroked with a violin bow so that it oscillates at its fundamental frequency. The water level in the tube is then lowered until a resonance is obtained, which occurs at 20 cm below the top of tube. Find the speed of sound in air. Respond in units of m/s.
Q2. An airplane starting from airport A flies 280 km east, then 365 km at 29.0° west of north, and then 130 km north to arrive finally at airport B.
The next day, another plane flies straight from A to airport B in a straight line. In what direction have to the pilot travel in this direct flight? (Suppose there is no wind during these flights.)