Two speakers are placed 500 meters away from each other. A person stands right in the middle of the two speakers. One of the speakers sends a sound wave traveling at 343m/s towards the person standing in the middle and the other speaker sends a sound wave traveling at 342m/s. How long after the person in the middle hears the first sound wave will he hear the second wave ( ) (please answer the question with unit of seconds)

Aspring with a mass of 2 kg has a damping constant 14 kg/s. a force of 3.6 n is required to keep the spring stretched 0.3 m beyond its natural length. the spring is stretched 0.6 m beyond its natural length and then released. find the position of the mass at any time t. (assume that movement to the right is the positive x-direction and the spring is attached to a wall at the left end.)

Moon effect. some people believe that the moon controls their activities. if the moon moves from being directly on the opposite side of earth from you to being directly overhead, by what percentage does (a) the moon's gravitational pull on you increase and (b) your weight (as measured on a scale) decrease? assume that the earth–moon (center-to-center) distance is 3.82 × 10^8 m, earth's radius is 6.37 × 10^6 m, moon's mass is 7.36 × 10^22 kg, and earth's mass is 5.98 × 10^24 kg.

In a system, when potential energy decreases, then entropy also decreases. true false