Problem No. 1 Figure below shows the merging of two streams to form a river. One stream has a width oh 8.2 m, depth of 3.4 m and current speed of 2.3 m/s. The other stream is 6.8 wide, 3.2 m deep and flow at 2.6 m/s. The width of the river is 10.5 m and the current speed is 2.9 m/s. What is its depth ? Answer : 4 m

Problem No. 2 A garden hose having an internal diameter of 0.75 in is connected to a lawn sprinkler that consists of an enclosure with 24 holes, each in in diameter. If the water in the hose has speed of 3.0 ft/s, at what speed does it leave the sprinkler holes ? Answer : 28 ft/s 1 in = 2,54 cm, 1 ft = 30,48 cm

Problem No. 3 The Goodyear blimp Columbia is cruising slowly at low altitude filled as usual with helium gas. Its maximum useful payload, including crew and cargo is 1280 kg. How much more payload could the Columbia carry if you replaced the helium gas with hydrogen gas ? The volume of the helium-filled interior space is 5000 m 3 The density of helium gas is 0,16 kg/m 3 m and the density of hydrogen is 0,081 kg/m 3 Answer : 390 kg

Problem No. 4 A car has a total mass of 1800 kg. The volume of air space in the passenger compartment is 5 m 3. The volume of the motor and front wheels is 0.75 m 3 and the volume the rear wheels, gas tank, trunk is 0.8 m 3. Water cannot enter these areas. The car is parked on a hill into lake. The handbrake cable snaps and the car the car rolls down the hill into the lake. a). At first, no water enters the passenger compartment. How much of the car in m 3 is below the water surface with the car floating as shown ? Answer : 1.8 m 3

A car has a total mass of 1800 kg. The volume of air space in the passenger compartment is 5 m 3. The volume of the motor and front wheels is 0.75 m 3 and the volume the rear wheels, gas tank, trunk is 0.8 m 3. Water cannot enter these areas. The car is parked on a hill into lake. The handbrake cable snaps and the car the car rolls down the hill into the lake. b). As water slowly enters, the car sinks. How many m 3 of water are in the car as it disappears below the water surface ? (The car remains horizontal. Owing to a heavy load in the trunk). Answer : 4.75 m 3

Problem No. 5 A water pipe having a 1.0 in diameter carries water into basement of a house at speed of 3 ft/s and pressure 25 lb/in 2. If the pipe taper to 0.5 in and rises to second floor 25 ft above the input point, what are a). What is the speed at the second floor ? Answer : 12 ft/s b). What is the pressure at the second floor ? Answer : 13 lb/in2 1 in = 2,54 cm, 1 ft = 30,48 cm 1 atm 1.013x10 5 Pa = 14.7 psia = 14.7 lb/in2

Problem No. 6 The total effective blade area of a small windmill is 4.6 m 3. a). What is the maximum possible power of the windmill generator when a steady wind is blowing at 6.7 m/s ? Answer : 830W b). What does this power become if the wind speed increases by 10 % ? The density of air is 1,2 kg/ m 3 Answer : 1105 W