Homework SourseA car is traveling up hill 6 grade at the rate of 85 kmh The
A car is traveling up hill (6% grade) at the rate of 85 km/h. The engine consumes 16.8 L/h while overcoming a drag force of 1000 N. If the fuel is ethanol (22.3 MJ/L), and the drive-train is 100% efficient, what is the fuel economy of the car in km/L?
A gage on a pressure vessel reads 32.19 psi. If the local atmospheric pressure is 754 mm Hg, what is the absolute pressure (kPa) of the gas contained inside of the vessel?
Water from a well is provided to replacement dairy heifers (cows) on pasture. There are a total of 60 cows in the herd. Assume each cow consumes 42.0 gallons of water per day. The well that supplies water to the stock tank is 450 feet deep (depth from soil surface to water level in well). Assume the pump is to run no more than three hour per day to pump enough water to meet the needs of the cows on pasture. An electric motor is used to power the pump. When operating at 220 VAC, what is the current draw (Amps) of the motor? Assume the overall efficiency of the pump and motor combination is 85%.
The adult human aorta has an inside diameter of approximately 24 mm. The heart has a stroke volume of approximately 85 ml. Assume the heart beats at a rate of 65 beats per minute. What is the average velocity (m/s) of the blood flowing through the aorta?
The absolute viscosity of water at 37oC is 0.00093 N. s/m2 . Water flows through a pipe at an average velocity of 52.3 cm/s. Assuming the pipe is 9.0 m in length, and 25 mm in diameter (inside), what is the value of Reynold\'s Number?
Solution
a) Let slope of hill be ao
tan a = 0.6
thus a = 30.96o
Let v be the velocity of car in linear direction hence vcos a will be velocity in x direction
Fuel economy of car = vcos a / 16.8
hence Fuel economy of car = 4.338 km/L
b) 1 psi = 6.894 kPa
thus 32.19 psi = 221.917 kPa
1 mm of Hg = 13600 x 9.81 x 0.001 = 0.1334 kPa
thus 754 mm of Hg = 100.58 kPa
Hence absolute pressure = Atmospheric Pressure + Gauge Pressure
absolute pressure = 100.58 + 221.917 = 322.497 kPa
