A door of dimension 1.5 m x 2.5 m and sound reduction index R = 50 dB is set into a wall of dimension 10 mx 3 m and sound reduction index, R = 75 dB. Determine the following: Sound reduction index of the partition if the door fits perfectly Sound reduction index of the partition if a gap of 5 mm exists around the door

A door of dimension 1.5 m x 2.5 m and sound reduction index R = 50 dB is set into a wall of dimension 10 mx 3 m and sound reduction index, R = 75 dB. Determine the following: Sound reduction index of the partition if the door fits perfectly Sound reduction index of the partition if a gap of 5 mm exists around the door

Construction Materials, Methods and Techniques (MindTap Course List)

4th Edition

ISBN:9781305086272

Author:William P. Spence, Eva Kultermann

Publisher:William P. Spence, Eva Kultermann

Chapter32: Acoustical Materials

Section: Chapter Questions

Problem 13RQ

See similar textbooks

Similar questions

10-3. Determine the sum of the following sound levels (all in dB): 68, 82, 76, 68, 74, and 81. Answer: 85.5, or 86, dB
1. A sound has a magnitude of 40 dB at 100m from its source. What is the magnitude at 50m from the source? 2. Define: a. dBA scale b. threshold shift
b) Table Q2(b) shows booking of a two-peg test. i). Calculate the reduced levels of point B ii). Calculate the collimation error after the two-peg test Table Q2(b). Two-peg test booking BS FS Height of Collimation (m) Reduced Level (m) Remark Distance, L = 60 m (Set 1) 1.653 10.000 A 1.322 1.406 В 1.567 A Distance, L = 60 m (Set 2) 1.614 1.498 1.366 10.000 A B A 1.742
A 4.50m high noise barrier results in a Path Length Difference of 1.4855m. Calculate the Fresnel Number (N accurate to three decimal places) for this scenario if the noise has a frequency of 900 hertz.
If the rms sound pressure is 5lb/ft2, what is the sound pressure level?
Question 4 a) Determine the rise in water level h as a result of surface tension between two glass surfaces of length I = 12 cm spaced d = 0.3mm apart with contact angle 0 = 3.6 degrees. l = 12cm b) If the distance between the two glass surfaces remained unchanged and the length of the glass surfaces decreased to | = 10cm, would the rise in water level h change or remain constant? %3D h =? d - 03mm
Do we see any negative effects on the acoustic performance of a room whose inner surfaces are mostly covered with porous materials? What are your suggestions for correcting these problems.
Only attempt if you know the right answer. Else downvoted A partition of total area 20m². consists of a brick wall plastered on both sides to a total thickness of 250mm and contains a windows of area 3m². The brickwork gives a sound reduction of 65dB and the window 22dB at a certain freq. Calculate the sound reduction of the complete partition at this freq.
A 30m tape has the following conditionThe standard temp is 20deg Celsius and the site temp is 27deg Celsius resulting to a temperature correction factor=0.02m for the 30 m tapeThe standard pull is 5 kg but the applied pull is 4.5 kg resulting to a correction due to pull= -0.01m for the 30 m tape. a) Determine the reading to be laid out to get a length of 30mb) Determine the reading to be laid out to get a length of 1300m
Problem 1 In the two-peg of a dummy level, the following abservation are taken. INSTRUMENT SET UP NEAR A INSTRUMENT SET UP NEAR B Rad Reading on A 0.921 0.367 Rad Reading on B 1430 0.768 a. What is the difference in elevation between A and 8? Answer: b. If the line of sight is not in adjustment, determine the correct rod reading an B with the instrument still set up at A. Answer:
Q1. A room has dimensions 12 m x 14 m x 6 m and average absorptivity of the surfaces is a = 0.2 If an 3x10^(-2) W average output acoustic source is placed in the center of the front wall find out the value of critical distance
10-12. Compute the average sound pressure level of the following readings by simple arithmetic averaging and by logarithmic averaging (Equation 10-13) (all readings in dB): 42, 50, 65, 71, and 47. Does arithmetic averaging un- derestimate or overestimate the sound pressure level? Answers: x 55.00 or 55 dB L, = 61.57, or 62, dB