Question

Apollo 8 orbited the moon in a circular orbit. Its average altitude was 185 km above the moon's surface. Create an equation to model the path of Apollo 8 using the center of the moon as the origin. Note that the radius of the moon 1,737 km.
a. x^2+y^2=34,225
b. x^2+y^2=2,408,704
c. x^2+y^2=3,017,169
d. x^2+y^2=3,694,084

I am a little confused with this. Please help ;)

Answer 1

What is difficult here?

Equation of a circle:

x² + y² = r²

x² + y² = 1,737²

x² + y² = 3,017,169

Answer c.

Answer 2

Correction.

I forgot altitude.

R = r + 185 = 1,737 + 185 = 1,922

x² + y² = R²

x² + y² = 1,922²

x² + y² = 3,694,084

Answer d.

Answer 3

I believe that is correct. It matches what I did on paper.

Answer 4

Bosian is 100% correct for x² + y² = 3,694,084

Answer d.

As for rest correct answers are

1. B (x-4)^2+(y+5)^2=4
2. C (x+2)^2+(y-2)^2=13