Partial Exam 4
FISI-3171
Apr. 29, 2009
Dr. LU
1. The principle used to calculate buoyant force was discovered by (5 points)
(a) Newton
(b) Bernoulli
(c) Archimedes (d) Pascal
2. In a simple harmonic oscillation, the constant ω typically represents the (5 points)
(a) Wavelength
(b) Amplitude
(c) Angular frequency
(d) Phase angle
3. Which physical quantity is not changed when a harmonic wave is transmitted
from a thin cord to a thicker cord? (5 points)
(a) Wavelength (b) Amplitude (c) Frequency (d) Wave number
4. The pitch of a sound is determined by its (5 points)
(a) Intensity
(b) Power
(c) Frequency (d) Speed
5. The specific gravity of ice is 0.917, whereas that of seawater is 1.025. What
percent of an iceberg is above the surface of the water? (20 points)
6. A spring with spring constant k = 9.80 N/m is placed horizontally. A 0.200-kg
mass is attached at the end of the spring and placed on a frictionless table. The
other end of the spring is fixed to a wall. The mass is pushed so that the spring is
compressed 0.300 m from the equilibrium point, and released from rest.
Determine:
(a) the displacement x as a function of time t; (10 points)
(b) the velocity v at t = 0.100 s; (10 points)
(c) the total energy E; (10 points)
(d) the velocity when the mass is 0.150 m away from equilibrium. (10 points)
7. A standing wave in a piano string with 1.10 m length and 9.00 g mass has three
nodes and frequency 262 Hz. Calculate
(a) The wave length of the standing wave; (10 points)
(b) The tension force in the string. (10 points)
Bonus problem
The displacement of a transverse wave traveling on a string is represented by
D1 = 4.2 sin(0.84 x − 47t + 2.1) , where D1 and x are in cm and t in s.
(a) Find an equation that represents a wave which will produce a standing wave when
added to this one; (10 points)
(b) What is the equation describing the standing wave? (10 points)