In: Physics
a. If the intensity of sound from a jet engine is 10 W/m 2 at a distance of 30 m, how far away from the jet do you have to be for the intensity to be 0.1 W/m 2 ?
b. Suppose that you hear a clap of thunder 5 s after seeing the lightning stroke. If the speed of sound in the air is 343 m/s and the speed of light in air is 3 × 10 8 m/s, how far are you from the lightning strike?
c. How long is the time gap between ultrasound reflections from the front and back of the heart, assuming the heart to be modeled as a cube of edge length 15 cm?