You are trying to tune the fifth string on your guitar, which is supposed to sound the A2 note (i. e., a note two octaves below A4). If the part of your guitar string in between where it is held down is 1.2 m and it has a mass of 0.006 kg, how much tension should you put the string under to get the right tuning?

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.