A 75.0-kg floats in freshwater 3.00% of his volume above water when his are empty, and 5.00% of his volume above water when his lungs are full. Calculate the volume of air inhales—called his lung capacity—in liters. (b) Does lung volume seem reasonable?

A frequency quoted rule of thumb aircraft design is that wings should produce about 1000 N of lift per square meter of wing. (The fact that a wing has a top and bottom surface does not double its area.) (a) At takeoff, an aircraft travels at 60.0 m/s, so that the air speed relative to the bottom of the wing is 60.0 m/s. Given be sea level density of air as 1.29kg/m3, how fast must it move over be upper surface to create the ideal lift? (b) How fast must air move over the upper surface at a cruising speed of 245 m/s and at an altitude where air density is one-fourth that at sea level? (Note that his not all of be aircraft's lift—some comes from be body of the plane, some from engine thrust, and so on. Furthermore, Bernoulli's principle gives approximate answer because flow over wing creates turbulence.)

How many cubic meters of helium are required to lift a light balloon with a 400-kg payload to a height of 8 000 m? Take Hc = 0.179 kg/m3. Assume the balloon maintains a constant volume and the density of air decreases with the altitude z according to the expression pair = 0e-z/8 000, where z is in meters and 0 = 1.20 kg/m3 is the density of air at sea level.