A piece of copper weighing 400 g is heated to 100 oC and then quickly transferred to a copper calorimeter of mass 10 g containing 100 g of liquid of unknown specific heat capacity at 30 oC. If the final temperature of the mixture is 50 oC, calculate the specific heat capacity of the liquid. (Specific heat capacity of copper = 390 J kg-1 K-1)

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