(Solved):   The hot-air balloon shown in Figure Q4 below contains air having a temperature of \( 80^{\ ...

 

The hot-air balloon shown in Figure Q4 below contains air having a temperature of \( 80^{\circ} \mathrm{C} \), while the surrounding air has a temperature of \( 20^{\circ} \mathrm{C} \). Compute the volume of hot air if the total mass of the balloon and the load is \( 770 \mathrm{~kg} \). Take the densities of the air inside the balloon at \( 80^{\circ} \mathrm{C} \) as \( 1.000 \mathrm{~kg} / \mathrm{m}^{3} \) and air outside the balloon at 20 \( { }^{\circ} \mathrm{C} \) as \( 1.202 \mathrm{~kg} / \mathrm{m}^{3} \). Figure Q4: Schematic of hot air balloon