1.A person's heartbeat averages around 80 beats per minute. Calculate the period in seconds and the frequency in hertz?

2.Find the wavelength and period of an 18-Hz sound wave, which is one of the lowest frequencies detectable by the human ear. Assume the speed of sound in air is 343 m/s.

3.Find the frequency and period of a sound wave moving through iron at 25C with a 25.0 cm wavelength. Assume the speed of sound in iron is 5130 m/s.