+25 instant points+

guys so in engineering ive been struggling a lot.

how do you find sin cos and

does anyone know about scalars and vectors.

my teacher wont pass this concept and im stuggling. my friends almost immediantly understood everything while i havent even started.

reccomend me videos.

is there a formula to solve like ive heard my teacher say suc a toe sumthing

. i have a test

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?