(i) A solid 1.5-m-diameter sphere floats at the interface between water (SG = 1.0) and mercury (SG = 13.56) such that 30 percent is in the water. What is the specific gravity of the sphere?
(ii) A 10-m-diameter balloon contains helium at 125 kPa absolute and 15°C, moored in sea-level standard air pressure of 101 kPa and 25oC. If the gas constant of helium is 2077 m2/(s2·K) and balloon material weight is neglected, what is the net lifting force of the balloon in kN?