Applet: Tidial Acceleration by the Moon and the Sun

High tides at the sublunar point and its antipodal point at New Moon and Full Moon.
The tidal forces of the Moon is reinforced by the Sun (spring tide):
a ≈ aMoon + aSun ≈ (1.1 + 0.50)⋅10^-6 m/s² = 1.6⋅10^-6 m/s²

tidal force moon sun

When the Moon is at first quarter or third quarter (Sun and Moon separated by 90° when viewed from the Earth) the solar tidal force partially cancels the Moon's (neap tide):
a ≈ aMoon - aSun ≈ (1.1 - 0.50)⋅10^-6 m/s² = 0.60⋅10^-6 m/s²

The axial tidal acceleration a by the Moon is approximately:

tidal force formula

Earth's radius r=6371 km, Moon's mass M=7.349 10²² kg, mean distance Earth-Moon R =384401000 m:
aMoon ≈ 1.1⋅10^-6 m/s²
Sun's mass M=1.989 10³⁰ kg, mean distance Sun-Earth R=1.496⋅10¹¹ m
aSun ≈ 0.50⋅10^-6 m/s²

The applet is using the ecliptical geocentric longitudes of the Moon and the Sun (neglecting their declinations), and the geocentric distances of the bodies.

Select "Draw Tides" from the "Details" menu:
tidal force diagram

The applet is also computing the geocentric and topocentric distance of the Moon from the Earth (kilometers), the apparent angular size (arc minutes), the illuminated fraction of the Moon's disc (per cent), and the Moon's phase:

0.00 = new Moon
0.25 = first quarter
0.50 = full Moon
0.75 = last quarter
1.00 = new Moon

The altitude is taking into account the horizontal parallax of the Moon.

	Distance / km
Perigee	356,375
Mean	384,401
Apogee	406,720

Select "Write Data" from the "Details" menu:

F(EM)/F(SM) is the ratio of the gravitation forces between Earth and Moon F(EM) to Sun and Moon F(SM).
The mean value of about 0.45 for the Earth's Moon is unique in the solar system:
Details

Select "Diagram" from the Details menu:

earth moon distance

The change of distance may be up to about 6,300 km per day.

The mean perigee distance of 284 anomalistic months is 362562.4 km.