DYNAMICS - CASE STUDY SOLUTION

     


Velocity Direction


Carrier View


Earth View

 

Let the Nimitz be point A, and the F-15 be point B.

The origin of the x-y coordinate system is fixed relative to the earth.

The velocity of the Nimitz relative to the earth is

     vA = 15j knots

The velocity of the F-15 relative to the Nimitz is

     vB/A = 300 cos45i + 300 sin45j knots

Using the relative velocity equation, the velocity of the F-15 relative to the earth can be obtained as,

     vB = vA + vB/A
          = 300 cos45i + (15 + 300 sin45)j
          = 212.1i + 227.1j

The magnitude of the velocity of the F-15 relative to the earth is

     

Trigonometry can be used to find the direction of the
F-15 relative to the earth, giving

     θ = tan-1 (212.1/227.1) = 43.0o East of North