Physics 1301A/B Final: Physics 1301 + 1302 Exam Bank.pdf

An electron is accelerated from rest for a time of 10^-9 second bya uniform electric field that exerts a force of 8.0 x 10^-15 newtonon the electron.

1. What is the magnitude of the electric field?
(A) 8.0 x 10^-24 N/C
(B) 9.1 x 10^-22 N/C
(C) 8.0 x 10^-6 N/C
(D) 2.0 x 10^-5 N/C
(E) 5.0 x 10^4 N/C

Could you explain why as well? Thank you so much! :D

True or False

(I) Is each one of the following statements true or false for aphoton?

(a) It is a quantum particle, behaving in some experiments like aclassical particle and in some experiments like a classicalwave.TrueYour answer is correct.

(b) Its rest energy is zero. FalseYour answer is incorrect.

(c) Its rest energy is nonzero. TrueYour answer is incorrect.

(d) It carries energy in its motion. 4

(e) It carries momentum in its motion. 5

(f) Its motion is described by a wave function that has awavelength and satisfies a wave equation. 6

(g) For one-dimensional motion, the wave equation is asfollows:
(partial^2 E)/(partial x^2) = mu_0 epsilon_0 (partial^2 E)/(partialt^2)
where the wave function E is the electric field magnitude, with asimilar equation for B = E/c. 7

(h) For one-dimensional motion, the wave equation is asfollows:
-hbar^2/(2m)(d^2 Psi)/(dx^2) + U Psi = E Psi
where E is the constant energy. 8

(i) The intensity of the wave is proportional to the square of itswave function. 9

(j) The intensity of the wave is measured from the rate at whichthe quantum particles bombard a detector. 10



(II) Is each one of the statements true or false for anelectron?

(a) It is a quantum particle, behaving in some experiments like aclassical particle and in some experiments like a classical wave.11

(b) Its rest energy is zero. 12

(c) Its rest energy is nonzero. 13

(d) It carries energy in its motion. 14

(e) It carries momentum in its motion. 15

(f) Its motion is described by a wave function that has awavelength and satisfies a wave equation. 16

(g) For one-dimensional motion, the wave equation is asfollows:
(partial^2 E)/(partial x^2) = mu_0 epsilon_0 (partial^2 E)/(partialt^2)
where the wave function E is the electric field magnitude, with asimilar equation for B = E/c. 17

(h) For one-dimensional motion, the wave equation is asfollows:
-hbar^2/(2m)(d^2 Psi)/(dx^2) + U Psi = E Psi
where E is the constant energy. 18

(i) The intensity of the wave is proportional to the square of itswave function. 19

(j) The intensity of the wave is measured from the rate at whichthe quantum particles bombard a detector.

Elisha Graves Otis invented the elevator brake in the mid- , making it possible to build tall skyscrapers with fast elevators. Today’s skyscrapers are a large fraction of a mile tall; for example. Taipei in Taiwan has stories and is ( miles) tall. The top speed of the elevator in the Taipei tower is roughly three times greater than the ascent rate of a commercial jet airplane. The position and time data in the table are based on such an elevator.

a. Working in SI units, make a position-versus-time graph for the elevator.

b. Describe the motion of the elevator in words.

c. Find the highest speed of the elevator. When is the elevator going at this speed?

d. What sort of considerations would the engineers need to make to ensure the comfort of the passengers?