C - is the center of mass of the Earth and the Moon system.
A - is a point on the surface of the Earth.
O - is the center of the Earth.
| theta | alpha | gm | acx | acy | total g |
|---|---|---|---|---|---|
| 0 | 0 | 0.0000321 | 0.0000782 | 0.0000000 | 9.8066039 |
| 30 | 17 | 0.0000322 | 0.0000722 | 0.0000226 | 9.8066041 |
| 60 | 35 | 0.0000326 | 0.0000556 | 0.0000391 | 9.8066046 |
| 90 | 54 | 0.0000332 | 0.0000331 | 0.0000451 | 9.8066049 |
| 120 | 75 | 0.0000337 | 0.0000105 | 0.0000391 | 9.8066045 |
| 150 | 105 | 0.0000341 | -0.0000060 | 0.0000226 | 9.8066039 |
| 180 | 180 | 0.0000343 | -0.0000121 | 0.0000000 | 9.8066036 |
acx - x component of centrifugal acceleration due to Earth-Moon revolution.
gm - gravitational acceleration due to the Moon.
total g - total g sensed at the location A.
double G = 6.67408e-11; // m3/kg/s2
double mm = 7.342e22; // kg
double d = 3.844e8; // m
double R = 6.371e6; // m
double d2 = 4.67e6; // distance between C and O; unit: m
double omega = 2.66e-6; // 1/s
double rx = d2 + R * cos( theta );
double ry = R * sin( theta );
double alpha_radian = atan2( ry, rx );
double rr = sqrt( rx * rx + ry * ry );
double gc = rr * omega * omega;
double acx = gc * cos( alpha );
dm = d + R * cos( theta )
gm = G * mm / ( dm * dm )