Acoustics Answers

A lift is filled with patients has a total mass of 2055 kg. As the lift begins to go up, the acceleration is 0.75 m/s2. What is the tension in the rope that is lifting the lift? Validate your solution as well.

A bus’s tire rotates at an initial angular speed of 20.5 rad/s. The driver accelerates, and after 4.5 s the tire’s angular speed is 29.0 rad/s. What is the tire’s average angular acceleration during the 4.5 s time interval?

In 100 seconds a smoke alarm emits 1 000 000 sound waves. What is the frequency of the sound waves?

A sound pulse ( like a loud clap ) is directed toward the wall of a tall building that is 680 m from the source of the sound. The reflected wave is detected 4.0 seconds after the pulse is produced.

A) how long does it take the pulse to reach the building?
B) what is the speed of the sound pulse?

Given that the maximum force your forehead can take is about 6000N, while the maximum
force your cheekbone can take is 1300N. If a 0.14 kg solid ball strikes any part of your head at
39 m/s and stops in 1.2 × 10−3 s, which of the following is correct:
a) Only your forehead will be in danger of fraction.
b) Nor your forehead neither your cheekbone will be in danger of fraction
c) Only your cheekbone will be in danger of fraction.
d) Both your forehead and your cheekbone will be in danger of fraction
e) I cannot decide because the mass of the head is not known

what is density

What do you understand by wave impedance? Derive an expression for the
impedance offered to sound waves propagating in a gaseous medium.

For a metal rod, the value of Young’s modulus is 1.5X10^11 Nm^-2 and density is 7500 kgm^-3
Calculate the speed of sound in the metal rod.

Calculate the fundamental frequencies and the first 3 overtones of a pipe of length 1.7 m
and closed at one end.