A balloon filled with helium gas has an average density of ρb = 0.31 kg/m3. The density of the air is about ρa = 1.23 kg/m3. The volume of the balloon is Vb = 0.075 m3. The balloon is floating upward with acceleration a.  Express the total force F in terms of W and Fb assuming upward is the positive direction.

A spherical submersible 2.00 m in radius, armed with multiple cameras, descends under water in a region of the Atlantic Ocean known for shipwrecks and finds its first shipwreck at a depth of 1.75 103 m. Seawater has density 1.03 103 kg/m3, and the air pressure at the oceans surface is 1.013 105 Pa. a. What is the absolute pressure at the depth of the shipwreck? b. What is the buoyant force on the submersible at the depth of the shipwreck?

The gravitational force exerted on a solid object is 5.00 N. When the object is suspended from a spring scale and submerged in water, the scale reads 3.50 N (Fig. P15.24). Find the density of the object. Figure P15.24 Problems 24 and 25.

A manometer containing water with one end connected to a container of gas has a column height difference of 0.60 m (Fig. P15.72). If the atmospheric pressure on the right column is 1.01 105 Pa, find the absolute pressure of the gas in the container. The density of water is 1.0 103 kg/m3. FIGURE P15.72