Centripital Force or Centrifugal Force, which one keeps the moon in orbit with the Earth?

Question

If centripital force is centre seeking then why when e.g. gravity is overcome does the satelite fly off and not toward the object it was orbiting. What was the force called acting against the centre (seeking) force. Is this not centrifugal?

Answer 1

The Moon is kept in orbit by the help of centripetal force and centrifugal force.
These two forces are equal on a certain point of the orbit, so the Moon cannot fall on Earth and cannot goes away from the Earth.

Centripetal Force is the force that constrains a material particle to follow a curved path and that acts inwardly toward the center of curvature of the path causing centripetal acceleration.

For the calculation of the centripetal force following formula is used:

Fp = m * v square / r

v is the peripheral speed vector on the periphery of the circle.

v square is v multiplied by v . ( v * v )
The unit of v is meter per second.
m is the mass of the object ( for instance the moon's mass).
The unit of mass is kilogram.

r is the distance between the object and the center of the movement.
The unit of the r is meter.

The centripetal acceleration equals to ( v *v / r )

Centrifugal force is the force that a material particle moving along a curve exerts on the body constraining the motion and that is directed outwardly along the radius of the curve ( that is the reaction to the centripetal force ).

For the calculation of the centrifugal force following formula is used:

Fc = - m * v square / r

Consequently: centrifpetal force borns from the mechanical rules ( Newtonian ). Centrifugal force is a reaction to centripetal force, because of the mass of the Object ( Moon ).

Centripetal force acts invardly toward the center; Centrifugal force acts outwardly from the center. The Moon is being in a point where the two forces are equal.

If the peripheral speed ( v ) decreases, both the centripetal and centrifugal force decrease , then the moon goes inwardly (r radius decrease ) and the moon moves on a nearer trajectory of the Earth.
On a certain point the centripetal and the centrifugal forces shall be equal again and the Moon shall not fall on Earth , moves on the new trajectory.

Answer 2

If you are asking what is the force that causes the moon to orbit the earth then it is gravity. If you are asking whether it acts as the centripetal or the centrifugal force then it is the centripetal.

If we look at the problem from the point of view of the centre of the earth (not someone on the earth, since the earth rotating) then the moon is moving in a circle with the earth at its centre. Any object moving in a circle feels a resultant force at 90 degrees to the direction of its velocity that is directed towards the centre of the circle. In this case, this force is gravity alone.

Centrifugal force is a force that is felt by the moon but has no physical basis and has only arisen because the moon is accelerating. From the point of view of the moon it is motionless and the earth is moving, however just because we have changed our viewpoint does not mean that the earth has magically disappeared, so the moon still feels the earth's gravity. Since it is motionless it must also feel another force that is directed away from the centre of the earth and has the same magnitude as the gravitational force due to the earth. This is the centrifugal force and is known as a fictitious force since it is not due to a physical mechanism.

Please note that this is a simplified model. In actual fact the earth and moon orbit the centre of mass of the two objects however this is a good model since the earth much more massive than the earth and the position of the centre of mass is much closer to the earth than the moon. It has also not taken into account the presence of the sun (or the other planets, but they have a much lesser effect) however this is an extremely difficult task and no one has yet to discover the solution fully. If you are interested please research "the three body problem".

Jez

Answer 3

People often confuse the terms centripetal force and centrifugal force. In fact they describe the same thing but are opposite in sign. In science it is usual to use the term centripetal (centre seeking).

If an object moves on a circular path it seems to accelerate away from the centre since all objects will move in a straight line unless forced to do otherwise. This tendency for the object to fly off is commonly termed centrifugal force but is actually the result of the object trying to move in a straight line rather than a circular orbit. To restrain the object in its orbit requires an equal and opposite centripetal force. In the case of the moon the force is the gravitational pull of the Earth. In actual fact the moon is moving away from th Earth at a rate of a few centimetres per year or so. so strictly speaking the forces don't balance out completely

Answer 4

Jez gave you a perfect answer. Istanbulengineer gave a wrong answer that is typical of someone with only a partial understanding of orbital mechanics and Newton's Laws of Motion. (Specifically, centrifugal force is NOT the reaction force to centripetal force.)

Gravity keeps the Moon orbiting Earth. Gravity is a centripetal force in this situation.

Answer 5

Firstly Centrifugal force does NOT exist. Its is termed a pseudo force. In that it 'appears' to exist within a frame of refernce.

Think of a childrens playground and the roundabout. When you are on it you feel your being pushed out so you thin of centrifugal force. This is not what's happening but its what 'appears' to happen if your on the roundabout.

However for anyone observing from outside is clear you are not being pushed outwards.

Answer 6

for an object moving in a circle, there must be an inward force acting upon it in order to cause its inward acceleration. This is sometimes referred to as the centripetal force requirement. The word "centripetal" (not to be confused with the F-word "centrifugal") means center-seeking. For object's moving in circular motion, there is a net force acting towards the center which causes the object to seek the center.

Answer 7

Centripital.
look up the definition of centrifugal.

Answer 8

Do you desire to know one of the factors typical Law of attractionproduct does not work for so many people?Think it like a diet plan. If you want slim down and you strive to lose it

Answer 9

I thought it was the curving of space around the Earth's gravitational well. Gravity.

Answer 10

Centripital darling!