A spherical balloon that is to be used in air at 60°F and atmospheric pressure is tested by towing a 1/12-scale model in a lake. Th e model is 1.4 ft in diameter, and a drag of 37 lbf is measured when...

A spherical balloon that is to be used in air at 60°F and atmospheric pressure is tested by towing a 1/12-scale model in a lake. Th e model is 1.4 ft in diameter, and a drag of 37 lbf is measured when the model is being towed in deep water at 5 ft /s. What drag (in pounds force and newtons) can be expected for the prototype in air under dynamically similar conditions? Assume that the water temperature is 60°F.