Imagine yourself cutting grass with a gasoline-engine lawn mower. your ear is 2 meters from the source of the engine noise. your friend is standing nearby so that his ear is 10 meters from the source of the noise. a. if your ear is exposed to a sound pressure of 2.0 x 109upa, what is the amplitude of noise to which your friend is exposed? consider only the change in amplitude caused by the spreading out of the energy with distance from the source; do not consider damping. b. what is the ratio of the sound pressure on your ears as compared to the sound pressure on your friend's ears? (in other words, how many times more sound pressure is on your ears than his? )