SOLUTION: please help me solve this type of problem :A satellite orbits around the earth in an elliptical path of eccentricity 0.6 and semi-minor axis of length 12000 miles. if the center of

Algebra ->  Circles -> SOLUTION: please help me solve this type of problem :A satellite orbits around the earth in an elliptical path of eccentricity 0.6 and semi-minor axis of length 12000 miles. if the center of      Log On


   



Question 836757: please help me solve this type of problem :A satellite orbits around the earth in an elliptical path of eccentricity 0.6 and semi-minor axis of length 12000 miles. if the center of the earth is at one of the foci,find the maximum altitude of the satelite.
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!


On the graph, we will say the scale 1 unit = 1000 miles.

The equation of the ellipse might be x%5E2%2Fb%5E2%2By%5E2%2Fa%5E2=1, 
but we don't need that.

The center of the earth is at point C, one of the focal points of the
elliptical orbit of the satellite.  The red circle represents a cross section
of the earth.  We assume the radius of the earth is 4000 mile = 4 units.
The point S is the surface of the earth where the satellite is at its
highest distance above the surface of the earth.

We want to find the length of SA.

OB=b is the semi-minor axis and it is given as 12 units (12000 miles).

The Pythagorean relation for every ellipse is 

c²=a²-b²

We are given the eccentricity 0.6 = c%2Fa

So c = OC = 0.6*OA = 0.6a, and we are given b = OB = 12 (12000 miles)

Substituting

c%5E2%22%22=%22%22a%5E2-b%5E2

%280.6a%29%5E2%22%22=%22%22a%5E2-12%5E2

0.36a%5E2%22%22=%22%22a%5E2-144

144%22%22=%22%22a%5E2-0.36a%5E2

144%22%22=%22%220.64a%5E2

144%2F.64%22%22=%22%22a%5E2

225%22%22=%22%22a%5E2

15%22%22=%22%22a

So OA = a = 15

and OC = c = 0.6a = .6(15) = 9 = 

SC = 4 (radius =4000 mi.)

OS = OC-SC = 9-4 = 5

So SA = OS+OA = 5+15 = 20

So the maximum altitude of the satellite is 20000 miles.

Edwin