2. Which of the following characteristics of an
insulator is not correct?
A.
4.
B.
The conduction band is empty of
electrons.
Both the valence band and the
conduction band are completely filled.
The forbidden band is very wide.
The valence band is empty of
electrons.
C.
D.

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

An electron and a proton are held on an x axis, with the electron at x = + 1.000 m and the proton at x = - 1.000 m. part a how much work is required to bring an additional electron from infinity to the origin? express your answer with the appropriate units. part b if, instead of the second electron coming in from infinity, it is initially at x = + 20.00 m on the axis and is given an initial velocity of 100.0 m/s toward the origin, does it reach the origin? part c how close to the origin does it come?

Every winter i fly home to chicago. it takes 3 hours. what is my average speed?