Acustomer owns several shopping carts. a shopping cart is identified by a shopping_cart_id and contains several books. some shopping carts may contain more than one copy of same book. the database records the number of copies of each book in any shopping cart. at that time, more information will be needed to complete the transaction. usually, the customer will be asked to fill or select a billing address, a shipping address, a shipping option, and payment information such as credit card number. an email notification is sent to the customer as soon as the order is placed

Amass of 1.5 kg of air at 120 kpa and 24°c is contained in a gas-tight, frictionless piston-cylinder device. the air is now compressed to a final pressure of 720 kpa. during the process, heat is transferred from the air such that the temperature inside the cylinder remains constant. calculate the boundary work input during this process.

What precautions should you take to prevent injuries when dealing with heavy loads?

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?