A 40-mph wind blowing past your house speeds up as itflows up and over the roof. If

Obtain a photograph/image of a situation in which the concept of the stagnation pressure is important. Print this photo and write a brief paragraph that describes the situation involved.

At a given point on a horizontal streamline in flowing air, the static pressure is 2.0 psi (i.e., a vacuum) and the velocity is 150 ft/s. Determine the pressure at a stagnation point on that streamline.

A drop of water in a zero-g environment (as in the International Space Station) will assume a spherical shape as shown in Fig. P3.18a. A raindrop in the cartoons is typically drawn as in Fig. P3.18b. The shape of an actual raindrop is more nearly like that shown in Fig. 3.18c. Discuss why these shapes are as indicated.

When an airplane is flying 200 mph at 5000-ft altitude in a standard atmosphere, the air velocity at a certain point on the wing is 273 mph relative to the airplane. (a) What suction pressure is developed on the wing at that point? (b) What is the pressure at the leading edge (a stagnation point) of the wing?

Air flows over the airfoil shown in Fig. P3.20. Sensors give the pressures shown at points A, B, C, and D. Find the air velocities just above points A, B, C, and D. The air density is 0.0020 slug/ft3 .

Some animals have learned to take advantage of the Bernoulli effect without having read a fluid mechanics book. For example, a typical prairie dog burrow contains two entrancesa flat front door and a mounded back door as shown in Fig. P3.21. When the wind blows with velocity V0 across the front door, the average velocity across the back door is greater than V0 because of the mound. Assume the air velocity across the back door is 1.07V0. For a wind velocity of 6 m/s, what pressure differences, p1 p2, are generated to provide a fresh airflow within the burrow?

Estimate the pressure on your hand when you hold it in the stream of air coming from the air hose at a filling station. List all assumptions and show calculations. Warning: Do not try this experiment; it can be dangerous!

2013 Indianapolis 500 champion Tony Kanaan holds his hand out of his IndyCar while driving through still air with standard atmospheric conditions. (a) For safety, the pit lane speed limit is 60 mph. At this speed, what is the maximum pressure on his hand? (b) Back on the race track, what is the maximum pressure when he is driving his IndyCar at 225 mph? (c) On the straightaways, the IndyCar reaches speeds in excess of 235 mph. For this speed, is your solution method for parts (a) and (b) reasonable? Explain.

What is the minimum height for an oil (SG = 0.75) manometer to measure airplane speeds up to 30 m/s at altitudes up to1500 m? The manometer is connected to a Pitot-static tube as shown in Fig. P3.24.

A Pitot-static tube is used to measure the velocity of helium in a pipe. The temperature and pressure are 40 F and 25 psia. A water manometer connected to the Pitot-static tube indicates a reading of 2.3 in. Determine the helium velocity. Is it reasonable to consider the flow as incompressible? Explain.

A Bourdon-type pressure gage is used to measure the pressure from a Pitot tube attached to the leading edge of an airplane wing. The gage is calibrated to read in miles per hour at standard sea level conditions (rather than psi). If the airspeed meter indicates 150 mph when flying at an altitude of 10,000 ft, what is the true airspeed?

Estimate the force of a hurricane strength wind against the side of your house. List any assumptions and show all calculations.

A 40-mph wind blowing past your house speeds up as it flows up and over the roof. If elevation effects are negligible, determine (a) the pressure at the point on the roof where the speed is 60 mph if the pressure in the free stream blowing toward your house is 14.7 psia. Would this effect tend to push the roof down against the house, or would it tend to lift the roof? (b) Determine the pressure on a window facing the wind if the window is assumed to be a stagnation point.

(See The Wide World of Fluids article titled Pressurized eyes, Section 3.5.) Determine the air velocity needed to produce a stagnation pressure equal to 10 mm of mercury