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Selasa, 19 April 2016

GRE Physics 0177



1. Which of the following best illustrates the acceleration of a pendulum bob at points a through e ?


2. The coefficient of static friction between a small coin and the surface of a turntable is 0.30. The turntable rotates at 33.3 revolutions per minute. What is the maximum distance from the center of the turntable at which the coin will not slide?
(A) 0.024 m
(B) 0.048 m
(C) 0.121 m
(D) 0.242 m
(E) 0.484 m

3. A satellite of mass m orbits a planet of mass M in a circular orbit of radius R. The time required for one revolution is
(A) independent of M
(B) proportional to √m
(C) linear in R
(D) proportional to R3/2
(E) proportional to R2

4. In a nonrelativistic, one-dimensional collision, a particle of mass 2m collides with a particle of mass m at rest. If the particles stick together after the collision, what fraction of the initial kinetic energy is lost in the collision?
(A) 0
(B) 1/ 4
(C) 1/3
(D) 1/2
(E) 2/3

5. A three-dimensional harmonic oscillator is in thermal equilibrium with a temperature reservoir at temperature T. The average total energy of the oscillator is
(A) 1/2 kT
(B) kT
(C) 3/2 kT
(D) 3kT
(E) 6kT

Ans:




6. An ideal monatomic gas expands quasi-statically to twice its volume. If the process is isothermal, the work done by the gas is Wi . If the process is adiabatic, the work done by the gas is Wa . Which of the following is true?
(A) Wi = Wa
(B) 0 = Wi < Wa
(C) 0 < Wi < Wa
(D) 0 = Wa < Wi
(E) 0 < Wa < Wi

7. 
Two long, identical bar magnets are placed under a horizontal piece of paper, as shown in the figure above. The paper is covered with iron filings. When the two north poles are a small distance apart and touching the paper, the iron filings move into a pattern that shows the magnetic field lines. Which of the following best illustrates the pattern that results?

Ans: