Download Midterm Examination

THE INTERNATIONAL UNIVERSITY (IU)
VIETNAM NATIONAL UNIVERSITY - HCMC
ASSIGNMENT
SUBJECT: PHYSICS 2
GROUP: 8-10 STUDENTS
(To submit: the 27th MAY 2016)
Student Name:_______________________Student ID:___________________
1/ (20 pts) A metal tank with volume 3.10 L will burst if the pressure of the gas it contains
exceeds 100 atm.
(a) If 11.0 mol of an ideal gas is put into the tank at a temperature of 23.00C, to what
temperature can the gas be warmed before the tank ruptures? You can ignore the thermal expansion
of the tank.
(b) Based on your answer to part (a), is it reasonable to ignore the thermal expansion of the
tank? Explain?
2/ (20 pts) Estimate the mean free path, the average time per collision, and the average
number of collisions per second that each N2 molecule undergoes in air at room temperature and
atmospheric pressure. The diameter of an N2 molecule is 0.3 nm.
3/ (20 pts) You kick a soccer ball, compressing it suddenly to 2/3 of its original volume. In
the process, you do 410 J of work on the air (assumed to be an ideal gas) inside the ball.
(a) What is the change in internal energy of the air inside the ball due to being com-pressed?
(b) Does the temperature of the air inside the ball rise or fall due to being compressed?
Explain.
4/ (20 pts) A series of thermodynamic processes is
shown in the pV-diagram of the figure. In process ab, 150 J of
heat is added to the system, and in process bd, 600 J of heat is
added. Find
(a) the internal energy change in process ab;
(b) the internal energy change in process abd and the
total heat added in process acd.
5/ (20 pts)
(a) How many atoms of helium gas fill a balloon having
a diameter of 30.0 cm at 20.0°C and 1.00 atm?
(b) What is the average kinetic energy of the helium atoms?
(c) What is the root-mean-square speed of the helium atoms?
The end