R3: explain how a speaker works by explaining why each part is required. what role does the function generator play? what role does the magnet play? what role does the coil play? what role does the paper play?
pi3: summarize r3’s answer by explaining why the ta’s homemade earbud is so much superior to the one that you made.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?