Engineering Answers

A can of pumpkin puree 8.73cm diameter by 11.43cm in height is being heated in a steam retort in which the steam pressure is 100 kPa above atmospheric pressure. The pumpkin has a thermal conductivity of 0.83Jm's "C", a specific heat of 3770Jkg and a density of 1090kgm³. The temperature in the can prior to retorting was 20°C. Plot out the temperature at the centre of the can as a function of time until this temperature reaches 115°C. Assume is very high

Determine the force in each member of the truss shown. State whether each member is in tension or compression and tabulate the results. 

2. Determine the moments of inertia Ix and Iy of the shaded area, with respect to an axis passing through GH

and FH respectively.

A house with 200-m2 floor space is to be heated with geothermal water flowing through

pipes laid in the ground under the floor. The walls of the house are 4 m high, and there are 10

single-paned windows in the house that are 1.2 m wide and 1.8 m high. The house has R-19

(in h · ft² · °F/Btu) insulation in the walls and R-30 on the ceiling. The floor temperature is

not to exceed 40°C. Hot geothermal water is available at 90°C, and the inner and outer

diameter of the pipes to be used are 2.4 cm and 3.0 cm. Design such a heating system for this

house in your area.

Avoid radiation (assume)