It is one hot summer day, so your mom tells you and your friends that you can have ice cream when the train comes through town. You and your friends decide to have a contest to see who will hear the train first. You decide to jump into the swimming pool and listen under water. You think water will help you feel and see the sound vibrations easier. Mary sits on a chair and decides that since air is thinner, the sound will travel faster through a thinner medium. Johnny puts his ear to the ground because he saw it in an old cowboy movie, and that is what the Indians did to hear the cowboys coming from a distance. Who is correct? Explain why that person is correct.

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 740 n/m. it is initially at rest on an inclined plane that is at an angle of theta= 26 with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is uk = 0.17. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. the block's initial mechanical energy is 9.472 j. b. if the spring pushes the block up the incline, what distance l in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.