Question $1$

A $1\mathrm{.}5-m^3$ insulated rigid tank contains $2\mathrm{.}7kg$ of carbon dioxide at $100$kPa. Now paddle$-$wheel work is done on the system until the pressure in the tank rises to $150$kPa. Determine the entropy change of carbon dioxide during this process. Assume constant specific heats.

Question $2$

An insulated piston$-$cylinder device initially contains $300L$ of air at $120$kPa and $17C.$ Air is now heated for $15$min by a $200-W$ resistance heater placed inside the cylinder. The pressure of air is maintained constant during this process. Determine the entropy change of air, assuming $($a$)$ constant specific heats

Example $5$

The total mass, wing area, cruising speed, and air

resistance power of a small aircraft are $1800kg,42m^2,$

$280k\frac{m}{h}r,$ and $190$ kW $,$ respectively. Determine the lift

and drag coefficients of this airplane while cruising at an

altitude of $4000$ m $.$