8. 2 cars, with the exact same mass, are travelling on Sample Road, The black one is going faster than the blue one? Which car has more
kinetic energy? Why?

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.

The field between two charged parallel plates is kept constant. if the two plates are brought closer together, the potential difference between the two plates either a) decrease b) does not change c) increase?

Asled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slidesa distance d1 down the slope and then covers the distance d2 alongthe horizontal terrain before stopping. find the coefficient ofkinetic friction μk between the sled and the ground, assumingthat it is constant throughout the trip. find the coefficient of kinetic frictionμk. express your answer in terms of someor all of the variables d1, d2, and θ.