Question Video: Determining the Magnitude of the Force That Earth Acts on the Sun Physics • 9th Grade

The Sun acts on Earth by a force of magnitude 3.5 × 10²² N. What is the magnitude of the force with which Earth acts on the Sun?

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Video Transcript

The Sun acts on Earth by a force of magnitude 3.5 times 10 to the 22 newtons. What is the magnitude of the force with which Earth acts on the Sun?

We can answer this question by simply recalling Newton’s third law of motion. Newton’s third law states that interacting objects exert equal and opposite forces on each other. In other words, when a force is applied to an object, the object exerts an equal-sized force in the opposite direction to the applied force. This is Newton’s third law, and it’s important to remember that this applies to interactions between a pair of objects, such as the Earth and Sun.

We can draw a diagram to help illustrate this. The Earth and Sun are gravitationally attracted to each other. The Sun attracts the Earth, and the Earth attracts the Sun. Because of Newton’s third law, we know that these forces act in opposite directions and that they have equal magnitude.

So since the Sun acts on Earth by a force of magnitude 3.5 times 10 to the 22 newtons, we know that Earth also acts on the Sun by a force of magnitude 3.5 times 10 to the 22 newtons.