Apartition between guestrooms in a hotel is 9' x 22! the total absorption measured in the receiving guestroom is 600 sabins at 500 hz. the manufacturer's literature assures you that the tl of the partition is 47 db at 500 hz. determine the noise reduction between the two rooms at this frequency.

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.