Mini Practice Final

1. The speed of an aircraft is given to be 1250 km/h. If the speed of sound at that location is 315 m/s, the Mach number is

2. The gage pressure in a pipe is measured by a manometer containing mercury (ρ = 13,600 kg/m3). The top of the mercury is open to the atmosphere and the atmospheric pressure is 100 kPa. If the mercury column height is 24 cm, the gage pressure in the pipe is

3. A 75-cm-diameter spherical object is completely submerged in water. The buoyant force acting on this object is

4. A steady, incompressible, two-dimensional velocity field is given by (see pdf) where the x- and y-coordinates are in meters and the magnitude of velocity is in m/s. The linear strain rate in the x-direction in s−1 is

6. Consider water flow through a horizontal, short garden hose at a rate of 40 kg/min. The velocity at the inlet is 1.5 m/s and that at the outlet is 16 m/s. The hose makes a 90° turn to a vertical direction before the water is discharged. Disregard the weight of the hose and water. Taking the momentum-flux correction factor to be 1.04 at both the inlet and the outlet, the reaction force in the vertical direction required to hold the hose in place is

7. Air at 1 atm and 40°C flows in a 8-cm-diameter pipe at a rate of 2500 L/min. The friction factor is determined from the Moody chart to be 0.027. The required power input to overcome the pressure drop for a pipe length of 150 m is

8. Consider a sharp-edged pipe exit for fully developed laminar flow of a fluid. The velocity of the flow is 4 m/s. This minor loss is equivalent to a head loss of

9. A steady, two-dimensional, incompressible flow field in the xy-plane has a stream function given by (see pdf) where a, b, and c are constants. The expression for the velocity component v is

10. A car is moving at a speed of 70 km/h in air at 20°C. The frontal area of the car is 2.4 m2. If the drag force acting on the car in the flow direction is 205 N, the drag coefficient of the car is