"So, the Planet pulls on the moon bereason of gravity? Why doesn't the moon get pulled right into the Planet and also crash?" the kid asked. Physicist Rhett Allain answers.

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I strive to develop better explanations each day. I have a feeling that I have currently answered this question. However before, I want to attempt aacquire. The question was from a friend's child. He asked:

So, the Earth pulls on the moon bereason of gravity? Why doesn't the moon acquire pulled into the Earth and also crash?

What an excellent question.


What is gravity? It is an interactivity in between objects that have actually the building we contact "mass". Then what is mass? How around this definition (that is technically wrong yet still useful): mass is the variety of electrons, prolots, and also neutrons that consist of a things. With the mass, the gravitational interaction is a force with the complying with properties:

It counts on the mass of both of the objects affiliated in the interactivity.The higher the mass (for either object), the better the gravitational force.If you rise the distance in between the two objects, the gravitational force decreases.The gravitational pressure on one object in the interaction always is in the direction of the other object. In other words, the gravitational pressure is an attractive force.

There are numerous various other cool things about gravity, but this will be enough to obtain us started.


So I have a pressure on the moon. What carry out forces carry out to an object? In brief, you can say that pressures CHANGE the motion of the object. I think it would be a poor concept to say that pressures make things relocate. While that can not be technically wrong all the moment, it is at the incredibly leastern misleading. Let me look at 3 different instances for forces.

Force pushing in the exact same direction as the velocity of the object. Suppose an object is relocating to the left through a pressure pushing in the same direction? Here is a diagram of that case.


One single and constant force makes the object speed up in this case. Don't loss right into the widespread trap of thinking that a constant force makes a things move at a consistent rate. This just isn't true.

Force pushing in the opposite direction as the velocity of the object. This is almost the exact same situation as over, but for an object moving to the appropriate the force would certainly be to the left.


Here the object slows dvery own. But really, this isn't what I wanted to talk around. If the moon is orbiting the Earth at a consistent rate, it neither speeds up nor slows down.

Force pushing perpendicular to the velocity of the object. Let me speak to this a "sideways" pressure.

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If it is just a sidemeans force, the object doesn't speed up and also it doesn't slow-moving dvery own. It simply transforms. Of course, in order to exert a constant sidemethods pressure, the pressure would certainly need to suggest in a different direction as the object turns or it wouldn't still be "sideways". Here is an example. Take a ball at the finish of a string - or possibly a yoyo given that the string is already attached. Swing the ball about in a circle. Why does it move this way? The string pulls on the round. But considering that the string can only pull in the direction of the string (you can't press through a string), the sphere has actually a sidemethods pressure on it and also changes direction.