Four machines contribute the following noise levels in db to a worker's exposure:

machine 1 80 dba

machine 2 86 dba

machine 3 93 dba

machine 4 70 dba

(a) calculate the combined noise-level exposure for this worker.

(b) the offending machine is obviously machine 3. suppose that machine 3 was at a distance of 5 feet away from the worker when the 93 dba level was measured. determine how far away would machine 3 have to be moved to bring the worker's continuous 8-hour combined exposure from all machines down to the osha pel

Which of the following statements is true about women and minorities in early psychology? a. in the early 20th century, numerous graduate schools recruited women and minorities to study psychology. b. opportunities in higher education were limited for women and minorities in the early 20th century due to discrimination. c. despite some obstacles, there were numerous employment opportunities for women and minorities. d. women and minorities were often selected to do academic research in an effort to make the field more diverse.

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

Rohit is trying to tune an instrument