6. James walks 5 minutes East in which he walks a distance of 60 m. He then rests for 5 minutes before turning left and walks another 60 m in 5 minutes. a) what is his instantaneous
velocity before he rested? b) What was James' average velocity over the whole trip?

Consider an insulating crystal, made up of layers of atoms. what form would you expect the temperature dependence of the phonon heat capacity to approach at extremely low temperatures if the interlayer coupling is i)very strong (rigid coupling), and ii) very weak. explain.