Does the moon accelerates as it revolves around Earth? Why or why not?

Question

Does the moon accelerates as it revolves around Earth? Why or why not?

Answer 1

Yes. It is first of all accelerated by gravity all the time - that's why it is not moving in a straight line, but in a curve.

Next, this curve is no perfect circle, but a ellipse, which means that the speed of the moon decreases with increasing distance. So there is a small acceleration additionally to the plain movement around Earth.

Answer 2

Listen to Jason T.

Answer 3

all bodies in orbit are constantly accelerating since their velocities are changing and they are being acted upon by a force (gravity)

Answer 4

since it does not travel in a straight line, yes, it accelerates.

Answer 5

The moon does accelorate as because it isn't a constant distance from the Earth. When it is close, it speeds up. When it is farther away, the speed is slower.

Answer 6

Yes it does.

Acceleration is defined as a change in velocity. Velocity is a quantity defined by speed and direction. If your direction changes your velocity changes, even if your speed remains constant. Since a circular motion is a continually changing direction there is continual acceleration, even if speed remains the same.

Answer 7

The moon accelerates slightly as it approaches perigee and decelerates as it approaches apogee.

The two actions cancel thus the orbital speed remains fairly constant with the net decrease in orbital speed being only that attributable to entropy.

Answer 8

Urwumpe got it right!

there are two separate things to consider.

According to Newton;s 1st law things travel in a straight line at a constant speed (or at rest) unless a force acts on them.

There is the force of gravity acting on the moon to keep it in orbit - so it changes direction. This is centripetal accelerations, which acts perpendicular to the direction of motion.

Then there's the fact that the moon's orbit isn't circular.

When the moon is closer to the earth is is pulled harder than when it is farthest. Also the elliptical shape of the orbit means that the pull of earth isn't exactly perpendicular to the direction of motion.

This means that as the moon moves from apogee (furthest point) to perigee (nearest point) it speeds up, and as it moves from perigee to apogee is slows down.

All this applies to Earth's orbit around the sun too

Answer 9

I am not reading this out of a book but the answer is yes.  The truth is it is everything is always accelerating and decelerating.  It is very hard to find constants in the universe.  Even things that seem to be constants, are probably changing to a very very small degree.

I forget specifically how much of an oval the moon performs around the Earth,  but I can explain why it does this.

You have to first understand that the the satalites we send up into space opperate on the same concept as the moon.  A satalitte is basically an object with a mass that is always falling, but traveling fast enough away from the earth at the same time that it seems to just float around the earth.  imagine you are running very fast and jump.  You create a parabola under your feet.  Now try to imagine if there was nothing under you to catch your fall.  What would happen if you jumped and nothing was under you on your way back down, what would happen?  You'd travels down to the other side of the earth oppositely until it sucks you back to where you started.  Like an Oval.

Satalive are basically launched to travel very fast horizontally away from the earth, but with no air resistance it doesn't lose speed going side ways.  so if you were to make a graph from you standing directly on top of the earth going striaght sideways, there is room for you to fall.  Once you find the balance between mass, speed away, and the gravity of the earth pulling you down you can get an object to "float" around.  

The moon does the same thing as any other satalite!  It just has more mass and is farther away from the earth so it is always falling closer to the earth, but traveling away to balance its rotation around the earth.

Now the questionw as if it accelerates?  Yes!  As the object gets closer to the earth the gravity will pull on it more, causing it to speed up.  If speeds up fast enough that it launches it self away from the earth farther, and decellerates.  Because the earth isn't pulling on it as much.  Once it looses all its velocity goign away from the earth, it will start fo come back towards the earth again and accelerate agian.  And it repeats this forever!

Hope you understand now!  This was one of the subjects that blew my mind when I learned about it.