Define the following leveling terms by matching the words given to the appropriate explanations in the sentences below:
(a) vertical line, (b) level surface, and (c) benchmark.

1. that follows the local direction of gravity as indicated by a plumb line
2. that at every point is perpendicular to the local plumb line (the direction in which gravity acts).
3. natural or artificial, having a marked point whose elevation above or below a reference datum is known or assumed.

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

An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)

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?