45. Think & Calculate Two bumper cars move in a straight line with the following equations of motion:
What is th
a-
x = -4.0 m + (1.5 m/s)t
x2 = 8.8 m + (-2.5 m/s)t
(a) Which bumper car is has the greater speed?
(b) At what time do the bumper cars collide?

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.