Which of these create radio waves? a. changing electric and magnetic fields applied at right angles b. longitudinal waves traveling along the horizontal direction c. compressions traveling along the vertical direction d. transverse waves traveling at different speeds

The experiment done in lab is repeated, using a ball that has unknown mass m. you plot your data in the form of f 2 versus m/l, with f in rev/s, m in kg, and l in m. your data falls close to a straight line that has slope 3.19 m/(kg · s2). use g = 9.80 m/s2 and calculate the mass m of the ball.