A gas flows smoothly through a pipe. The pipe’s cross-sectional area contracts from 0.075 m2 to 0.025 m2. The gas enters the pipe moving at 1.8 m/s and leaves the pipe moving at 2.0 m/s. The density of the gas as it enters the pipe is 1.4 kg/m3. What is the ratio of the density of the gas where it enters the pipe to its density where it exits the pipe?
Water flows smoothly through a pipe at a speed of 1.66 m/s. The water then flows smoothly from the first pipe into and through a second pipe, at a speed of 1.22 m/s. What is the ratio of the cross-sectional area of the first pipe to that of the second pipe?
A fire hose has a length of 15 m and a cross-sectional area of m2. The hose ejects 1.6 kg of water that has a density of 1,025 kg/m3 per second. What is the time interval between the water entering one end of the hose and leaving the opposite end?