An echo is a reflection of sound against another surface. Suppose you are standing on one side of a canyon and you yodeled. Suppose the temperature is 20°C and the canyon is 750 m wide, how long does it take for you to hear the echo
of your yodel?

The magnitude of the amount of energy released by burning a fuel source, measured in energy per unit mass, is called its fuel value. note that the fuel value is the negative of the isobaric specific heat of combustion for the fuel. if all the energy obtained from burning 1.23 pounds of butane with a fuel value of 10.85 kcal/g is used to heat 128.0 kg of water at an initial temperature of 18.3 °c, what is the final temperature? note that 1 lb = 453.6 g.