Estimates the reynolds number of a soccer ball travelling at 40 miles/hour to be around 3.0 x 105. at this condition, the drag coefficient on the ball is estimated to be about 0.25. calculate the drag force (in lbf) on the ball assuming the density and viscosity of air are respectively 0.135 lbm/ft3 and 0.363 x10-6 lbf-s/ft2. the diameter of the ball is 0.75 ft. 20 points.

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