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What is the size of the gravitational force that Earth exerts on the Moon?

The mass of the Moon is #7.3510^22kg#, while that of Earth is #5.9810^24kg#. The average distance from the center of the Moon to the center of Earth is #384,400 km#.

Answer 1

We use Newton’s universal law of gravitation, #F = -G( m_1.m_2)/r^2# but be careful to convert the distance to base units (m)

#F = -6.67xx10^-11(7.35xx10^22xx5.98xx10^24)/(384xx10^6)^2#

I get #F = -1.99xx10^20# N

The minus sign in the answer is because force is a vector quantity, written as #vecF#, so the direction matters and it is in the opposite direction to the distance as measured outwards from the Earth.

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Answer 2

Elena Antonova

The Moon is subject to a gravitational force of about 1.98 x 10^20 Newtons from Earth.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

What is the size of the gravitational force that Earth exerts on the Moon?

The mass of the Moon is #7.35*10^22kg#, while that of Earth is #5.98*10^24kg#. The average distance from the center of the Moon to the center of Earth is #384,400 km#.

The mass of the Moon is #7.3510^22kg#, while that of Earth is #5.9810^24kg#. The average distance from the center of the Moon to the center of Earth is #384,400 km#.