The sound pressure level at a particular location in an underground carpark is lp_1. when a car starts it engine, the sound pressure level at the same point is lp_2. what would be the sound pressure level (in db) at that point due to the car engine only? lp_1 (db) = 68; lp_2 (db) = 72.5;

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Which of the following controllers anticipates the future from the slope of errors over time? a)-proportional b)-on/off c)-integral d)-derivative.

List and describe the attached tools in boxford cnc milling machine? and how many tools were used in your projects explain them?