NAME:______

P301 Background Survey—(Fall 2009)

Please answer the following questions to the best of your ability. I fully expect that very few, if any of you will know the answer to some of the questions, and that all of you will know the answer to only a few questions. I wish to establish if the incoming knowledge of the class is similar to my expectations for that incoming knowledge.

  1. What is your major?

Asto: 8; Physics/Appl. Phys: 16; Physics Educ.: 2 ; Chem/Biochem:6; Math: 5 ; Other: 3

  1. What is the highest-level math course you have yet taken?

Calc II: 14 Calc III/IV: 17; ODE/PDE: 6 ; Other: 3

  1. What is a typical value for the radius of an atom (roughly)?

10-6 m: 2 ; 10-7 m: 2 ; 10-9 m: 6 ; 10-10 m: 8 ; 10-11-10-12 m: 5 ; 10-16-10-31 m: 6 ; ??: 10;

  1. Does a clock on a space ship traveling at ¼ the speed of light run slower, faster, or at the same speed as a clock sitting here on Earth?

Slower: 35 Faster: 2 Same: 2 It depends: 1

  1. What is the Heisenberg uncertainty principle?

Position and velocity cannot be known simultaneously: 14

Position and momentum cannot be known simultaneously: 9

Position and energy cannot be known simultaneously: 3

The act of observation changes the thing observed: 2

???: 12

  1. How would you describe the basic structure of the atom?

Electrons orbiting a nucleus: 10

Electron cloud (or orbitals) surrounding a nucleus: 25

???: 5

  1. Are you familiar with Mathematica or any other symbolic manipulation computer package?

Yes (Mathematica/Maple the most popular): 10

No: 30

  1. From what process do stars get their energy?

Fusion: 28

Other: 4

???: 8

PLEASE TURN OVER

  1. Re-express the function y(x,t) = exp[ i(kx-t)] in terms of its real and imaginary parts using trigonometric functions. If you have never seen an expression like this before, please indicate this in the space below.
    cos(kx-t)+isin(ks-t): 6

Forgot: 16

???: 18

  1. Describe the meaning of the term “half-life”.

About half the class got this right, only about 6 had no idea, and the remainder had roughly the right idea, but were sloppy enough in their description that I couldn’t be sure that they really knew. It is the time taken for ½ of a radioactive substance to decay into something else. Note: the change in mass is small (it is certainly not the time taken for the mass to reduce by a factor of two) and it is applied to a large collection of particles, not a single particle.

  1. What is the solution to the differential equation: df(t)/dt = -f(t)?

F(t) =e-t: 8 ; uncertain: 29: wrong 3

  1. What is the Cosmic Microwave Background, and why is it significant?

Radiation left over from the Big Bang/Early Universe: 18

Static on your radio receivers: 2

??: 20

  1. Can you draw a simple table showing the basic constituent particles in “standard model of particle Physics?”

NO: 34

Made some attempt: 6

  1. Name three different types of radiation emitted by unstable nuclei and provide a concise description of the particle emitted from the nucleus in each case.



He nucleus, electron,photon): 12

??: 12

Other: 5

  1. Name two experimental consequences arising from Einstein’s two principles of special relativity.

??: 23

Slower clocks: 5

Bent starlight/curved space-time: 6 (really that’s general relativity)

Other: 6