Three shafts and four gears are used to form a gear train that will transmit 7.5 kW from the motor at A to a machine tool at F. (Bearings for the shafts are omitted in the sketch.) The frequency of the motor is 30 Hz and that the allowable stress for each shaft is 60 MPa. Use Figure P18 to answer questions 18 to 20.

An air compression refrigeration system is to have an air pressure of 100 psia in the brine tank and an allowable air temperature increase of 60°f for standard vapor compression cycle temperatures of 77 f entering the expansion cylinder and 14 f entering the compression cylinder, calculate the coefficient of performance a. 2.5 b 3.3 c. 4.0 d. 5.0

Heat transfer by is the fastest mode of heat transfer that requires no intervening medium. a)-conduction b)-convection c)-radiation d)-conduction and convection

List 3 options on how to reduce knocking problens during engine process,