Part A: a. Atmospheric pressure on Earth at its surface is 101 KPa (101 kilopasc
ID: 1611997 • Letter: P
Question
Part A:
a. Atmospheric pressure on Earth at its surface is 101 KPa (101 kilopascals or 101,000 N/m2). Which of these statements is true.
b. If we pump out the gas in a closed container leaving only 1 billionth of the original gas, there will only be about 1000 atoms left in the container.
c. The number of atoms or molecules in the container does not depend on temperature.
d. If we pump out the gas in a closed container leaving only 1 millionth of the original gas there will still be more than 1013 (10,000 billion) atoms per cm3 in the container.
e. The number of atoms or molecules in the container depends on what the gas is composed of.
Part B:
Suppose you want to build a musical instrument with a hollow pipe that is open at both ends. You will make it oscillate by blowing air across one end. If it has length 1.79. What frequency will it resonate at in Hz? Assume the speed of sound in warm moist air is 340 m/s?
Part C:
Match these sounds with the sound energy in dB (decibels).
0 dB
20 dB
40 dB
80 dB
100 db
140 dB
Hearing damage from prolonged repeated exposure
Hearing threshold
Severe pain and damage with short exposure
Quiet afternoon at home
Classroom lecture
Whispering voice
0 dB
20 dB
40 dB
80 dB
100 db
140 dB
A.Hearing damage from prolonged repeated exposure
B.Hearing threshold
C.Severe pain and damage with short exposure
D.Quiet afternoon at home
E.Classroom lecture
F.Whispering voice
Explanation / Answer
Part B)
L = length of pipe = 1.79 m
V = speed of sound = 340 m/s
fundamental frequency is given as
f = V/(2L)
inserting the values
f = 340/(2 x 1.79)
f = 94.97 hz
Part C
Hearing damage from prolonged repeated exposure-100
Hearing threshold-140
Severe pain and damage with short exposure-0
Quiet afternoon at home-20
Classroom lecture - 80
Whispering voice-40