& The Cessna 172 takes off successfully from an airport during a day in June (28 C) with a standard
pressure (102.3 kPa). Assume that the take-off speed is (105mph). How much drag is produced if
the coefficient of drag is 0.05 ? The Cessna wing area is 20.2 m2 and has a mass of 1,156 kg.
D = (C. Apv2)/2
Co= 0.05
A = 20.2 m2
V = 105 miles/hour
There are 1609.34 meters in a mile 105 * 1609.34/3600 meters/sec

Determine the time of the day and month of the year at which the peak sensible cooling load occurs for a top floor, north-eastern corner room of an office building in durban for the following conditions: floor area: 8 x 8 x 3 m east and north walls: 115 mm face brick (outside), 20 mm air space, 115 mm ordinary brick (inside) with 15 mm plaster roof construction: suspended plasterboard ceiling, 450 mm air space, 150 mm concrete, 75mm screed, waterproofing no heat transfer across other surfaces window area 3x 1,5 m high in north wall only. ordinary glass with venetian blinds. lights and occupants : from 07: 00 to 18: 00 average light density: 25 w/m2 number of occupants : 5 seated, light office work room temperature 24°c