The drag coefficient of a vehicle increases when its windows are rolled down of its sunroof is opened. A sport car has a frontal are of 1.672 m² and a drag coefficient of 0.32 when the windows and sunroof are closed. The drag coefficient increases to 0.41 when the sunroof is opened. Determine the additional power consumption of the car when the sunroof is opened at 120 km/hr. Given that: Density of air = 1.2 kg/m³ Sunroof closed Sunroof Cp=0.32 open CD = 0.41

A rectangular wing on an aircraft has a chord length of 1.6 m and span of 11 m flying in sky at the speed of 195 km/ h. A total aerodynamic force of 21kN is experienced by the wing at that speed. Determine the lift coefficient of the wing, if the lift to drag ratio is 5. Also, determine the lift coefficient, if the ratio is considered to be 3 . Take the density of the air to be 1.23  kg/ m3 .

Bill gets a job delivering pizzas. The pizza company makes him mount a sign on the roof of his car. The frontal area of the sign is A = 0.612 ft2, and he estimates the drag coefficient to be CD = 0.94 at nearly all air speeds. Estimate how much additional money it costs Bill per year in fuel to drive with the sign on his roof compared to without the sign. Use the following additional information: He drives about 10,000 miles per year at an average speed of 45 mph. The overall car efficiency is 0.332, ? fuel = 50.2 lbm/ft3, and the heating value of the fuel is 1.53 × 107 ft . lbf/lbm. The fuel costs $3.50 per gallon. Use standard air properties. Be careful with unit conversions.

The car shown in the figure below moves at a constant speed on a highway and has a drag coefficient Cpc of 0.32 with the windows and roof closed. What is the percent increase of horsepower needed to maintain the speed if the windows and roof are then opened? With the windows and roof open, the drag coefficient increases to Cpo = 0.43. Assume the frontal area remains the same. Windows and roof closed: CD=CDc Windows open; roof open: C₂=CDo

A truck has a drag coefficient based on frontal area of CD = 0:86. The truck has a mass of 12,750 kg and a frontal area of 10.5 m2. If the truck is traveling at constant speed on a level road, the forces retarding its forward progress are the drag and the rolling friction. The force due to rolling friction can be written asFrf = W*fr(1 + V/V0)where V is the truck speed in m/s, V0 = 30 m/s and fr (the coe¢ cient of rolling resistance) is approximately 0.008 for a truck on concrete or asphalt. Plot the total power the engine must supply as a function of truck speed, V . Comment on the relative importance of drag and rolling friction in the fuel consumption of the truck.

, A small aircraft has a wing area of 40 m2a lift coefficient of 0.45 at takeoff settings, and a total mass of 4000 kg. Determine (a) the takeoff speed of this aircraft at sea level at standard atmospheric conditions, (b) the wing loading, and (c) the required power to maintain a constant cruising speed of 360 km/h for a cruising drag coefficient of 0.035.

A rotary mixer is constructed from two circular disks as shown. The mixer is rotated at 60 rpm in a large vessel containing a brine solution (SG = 1.1, μbrine=1.07×10-3 Pa-s). Determine the appropriate coefficient of drag using Low Reynolds Drag Coefficient. Neglect the drag on the rods and the motion induced in the liquid. Estimate the minimum torque and power required to drive the mixer. only HANDWRITTEN answer needed ( NOT TYPED)

Consider an airfoil at 12◦ angle of attack. The normal and axial force coefficients are 1.2 and 0.03, respectively. Calculate the lift and drag coefficients.

The manufacturer of a car reduces the drag coefficient of the car from 0.38 to 0.33 as a result of some modifications in its shape and design. If, on average, the aerodynamic drag accounts for 20 percent of the fuel consumption, the percent reduction in the fuel consumption of the car due to reducing the drag coefficient is (a) 15% (b) 13% (c) 6.6% (d ) 2.6% (e) 1.3%

QUESTION 4 Determine the force due to drag on an automobile traveling at 70 miles per hour. Assume the automobile has a frontal area of 5 m² and a drag coefficient of 0.4. O 256 N O 1266 N 846 N O2131 N