4. (Automotive) Drag force is the force exerted on a moving vehicle thats caused by air resis- tance. The formula for this force is as follows:

F_d = (C_d* A * pV² ) / 2

F_d is the drag force (lbs). C_d is the coefficient of drag (dimensionless).

A is the vehicles front area (ft2). is the air density (lb/ft3). V is the vehicles velocity (ft/sec).

Using this formula, write, compile, and run a C++ program that determines the drag force on a vehicle having a front area of 30 ft2 and a drag coefficient of .26 thats moving at a velocity of 60 mi/hr (88 ft/sec). Although air density depends on both temperature and alti- tude, assume an air density of .0077 lb/ft3, which is the air density at sea level at 59 F. Your program should use the symbolic name DRAG_COEF for the coefficient of drag and AIRDENSITY for the air density.

After verifying that your program is working correctly, use it to determine the drag force on a car with a front area of 20 ft2. All other variables should remain the same as in Exercise 4a.