课程名称︰普通物理学甲上
课程性质︰化学系必修 地质系选修兼通识
课程教师︰王名儒
开课学院：理学院
开课系所︰物理系
考试日期（年月日）︰2020/1/9
考试时限（分钟）：120分钟
试题 :
1.There are four particles, each of mass 10kg； form a square with an edge
length 1.2m. If the edge length is reduced to 0.2m, what is the change in the
gravatational potential energy of the four-particle system?
(G＝6.67×10^-11Nm^2/kg^2)
2.A tank is filled with water to height H. A hole is punched in one of the
walls at a depth h below the water surface.What is the speed v of the water
emerging from the hole?
3.Write down the functional form of a simple harmonic oscillator and use the
e^(-λt) trial function to find out its solution. Note that the oscillator has
mass m, a spring force constant k, and a damping constant b.
4.Write down the functional form of a simple harmonic wave traveling on a
string in postitive x direction. You need to pinpoint its amplitude, wave
length and period of this wave with your notations.
5.Oscillation of a 500Hz tuning fork sets up standing waves in a string
clamped at both ends under a 100N tension. If the string has a mass density of
0.010 kg/m, what is the wave propogation speed? The standing wave has 4 loops.
What is the length of the string?
6.Two trains are traveling toward each other at 30.5 m/s relative to ground.
One train is blowing whistle at 600Hz.(a) What frequency is heard on the other
train in still air? (b) What frequency is heard on the other train if the wind
is blowing at 30.5 m/s toward the whistle and away from the listener?
(sound speed=330 m/s)
7.In outer space, a spacecraft with a surface temperature 100K and an area
200m^2 is receiving effectively 300K blackbody radiation from a nearby planet.
What is the net power gain of this spacecraft assuming the area facing the
planet is only 100m^2 and the surface emissivity is close to 1. The Stefan-
Boltzmann constant is about 5.67×10^-8 W/m^2K^4.
8.Write down the Maxwell speed distribution for an ideal gas molecule with
mass m and its thermal equilibrium temperature T. What is the rms speed of the
molecule?
9.In a proton therapy acclerator, protons travel around a circular path of 25m
in an evacuated chamber whose residual gas is at 300K and 1.0×10^-9 atm
pressure. (a) Calculate the number of gas molecule per cubic meter. (b) What
is the mean free path of the gas molecules of the gas molecules if the
molecule diameter is about 2.0×10^-2 cm?
10. For an ideal Stirling engine, find out the work, internal energy change,
heat transfer, and entropy change in the process (Va,Pd)→(Va,Pa) with one
mole mono-atomic ideal gas.
https://imgur.com/wpl3Tkk