A person standing a certain distance from an airplane with four equally noisy jet engines is experiencing a sound level of 141 dB. What sound level would this person experience if the captain shut down all but one engine? [Hint: Add intensities, not dB's.]

If we relied solely on the nonrenewable resources found in the u. s., which one would we run out of first at current usage levels? a. natural gas b. oil c. uranium d. coal

What is the coefficient of kinetic friction μk between the block and the tabletop?

According to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does maria's voyage take according to samir?