The propeller of a small airplane has a 2-m-diameter slipstream and produces a thrust of 3600 N when the airplane is at rest on the ground. Assuming p = 1.225 kg/m3 for air, determine (a) the speed of the air in the slipstream, (b) the volume of air passing through the propeller per second, (c) the kinetic energy imparted per second to the air in the slipstream.

Water is discharged from the hose with a speed of 42ft/sec. Determine the two possible angles the fireman can hold the hose so that the water strikes the building at B. Take S=20ft. VA = 40 ft/s 0 8 ft 4 ft

Three liquids that will not mix are poured into a cylindrical container. The volumes and densities of the liquids are 0.45 L, 2.6 g/cm³; 0.20 L, 1.0 g/cm³; and 0.40 L, 0.65 g/cm³. What is the force on the bottom of the container due to these liquids? One liter = 1 L = 1000 cm³. (Ignore the contribution due to the atmosphere.) N

A spring is attached to the bottom of an empty swimming pool, with the axis of the spring oriented vertically. An 25.0-kg hollow block of wood (p = 840 kg/m³) is fixed to the top of the spring and compresses it. Then the pool is filled with water, completely covering the block. The spring is now observed to be stretched twice as much as it had been compressed. Determine the percentage of the block's total volume that is hollow. Ignore any air in the hollow space. Number i Units In air X 2x www Submerged in water --Unstrained length

Suppose you spray your sister with water from a garden hose. The water is supplied to the hose at a rate of 0.497×10−3 m3/s and the diameter of the nozzle you hold is 5.41×10−3 m. At what speed v does the water exit the nozzle?

In a research facility, a person lies on a horizontal platform which floats on a film of air. When the person's heart beats, it pushes a mass m of blood into the aorta with speed v, and the body and platform move in the opposite direction with speed V. Assume that the blood's speed is 56.5 cm/s. The mass of the person + platform is 54.0 kg. The platform moves 5.95 ✕ 10−5 m in 0.160 s after one heartbeat. Calculate the mass (in g) of blood that leaves the heart. Assume that the mass of blood is negligible compared with the total mass of the person, and the person + platform is initially at rest. (Also assume that the changes in velocity are instantaneous.)

A uniform disk of mass 10.0 kg and radius of 0.248 m spins at 302 rev/min on a low-friction axle. It must be brought to a stop in 1.00 min by a brake pad that makes contact with the disk at an average distance of 0.218 m from the axis. The coefficient of friction between the pad and the disk is 0.499. A piston in a cylinder of diameter 5.00 cm presses the brake pad against the disk. Find the pressure required for the brake fluid in the cylinder. Pa Need Help? Read It

6.2

A cylinder is fitted with a piston, beneath which is a spring, as in the drawing. The cylinder is open to the air at the top. Friction is absent. The spring constant of the spring is 3600 N/m. The piston has a negligible mass and a radius of 0.010 m. (a) When the air beneath the piston is completely pumped out, how much does the atmospheric pressure cause the spring to compress? (b) How much work does the atmospheric pressure do in compressing the spring?   * I know that a is = 0.0088422743 m  but b is NOT 8.950712099 J (wrong) please show work of how to work part b.