# physics

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Using Newton's Law of Universal Gravitation, compare the effect of the Sun and the Moon on the tides.

Constants: Mass of the Moon, M☽= 7.348E22 kg. Moon's semi-major axis, a☽= 3.844E8 m. You can find the other constants you will need on the Astronomy Formula Chart.

(In Moodle, enter large numbers with scientific E notation. Example: 100 = 1.00*102 in scientific notation, or 1.00E2 in scientific E notation. Don't forget measurement units! If there are two blanks, enter the numerical value in the first blank, and the measurement unit in the second blank. Example: 1.0 m + 1.0 m = .)

Start with two equal volumes of ocean water, one on the near side of the Earth, and the other on the far side of the Earth. Assume the mass of each volume of water equals 1000 kg.

The pull of the Sun on the water on the near side of the Earth:
(G (Nm2)/kg2)(mass of sun, M☉ )(mass of water, 1000 kg) / (1 AU, Earth's semi-major axis, a♁ m - Radius of the Earth, R♁ )2 = (enter at least 5 significant digits)

The pull of the Sun on the water on the far side of the Earth:
(G (Nm2)/kg2)(mass of sun, M☉ )(mass of water, 1000 kg) / (1 AU, Earth's semi-major axis, a♁ m + Radius of the Earth, R♁ )2 = (enter at least 5 significant digits)

The tides are caused by difference in forces from the near side to the far side. The difference in the forces from sun = (enter at least 2 significant digits)

The pull of the Moon on the water on the near side of the Earth:
(G (Nm2)/kg2)(mass of moon, M☽ )(mass of water, 1000 kg) / (moon's semi-major axis, a☽ m - Radius of the Earth, R♁ )2 = (enter at least 3 significant digits)

The pull of the Moon on the water on the far side of the Earth:
(G (Nm2)/kg2)(mass of moon, M☽ )(mass of water, 1000 kg) / (moon's semi-major axis, a☽ m + Radius of the Earth, R♁ )2 = (enter at least 3 significant digits)

The tides are caused by difference in forces from the near side to the far side. The difference in the forces from moon = (enter at least 2 significant digits)

So the has a bigger influence on earth's tides than the .

• physics -

Mass35kg
Velocity 15mls