What is the need for introducing the concept of G.P.E?

In summary, GPE is introduced to help calculate the work done in a process where force is inconvenient.
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donaldparida
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What is the need of introducing the concept of gravitational potential energy in physics? Can't we simply say that when an object is lifted up it falls down because of the force of gravity acting on it instead of saying that it has G.P.E and so it is falls down?
 
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It is a useful tool in a lot of situations. For example, if you roll a ball down a ramp (or drop it off a cliff), you can easily figure out the final speed with only the height of the ramp (ignoring rotational inertia, drag and other losses).
 
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  • #3
Yes you are right, if a body is lifted up, it falls down due to gravitational pull.

I think GPE is introduced to explain the work done in the process.
A body cannot lift itself up on its own. You have to do work against the gravitational force to lift the body up. Now, whenever work is done, there has to be some kind of energy involved somewhere (workdone = change in energy).
The work you did should be stored in the object which is the GPE.
 
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  • #4
G.P.E. is so usefull because the mass of objects is so small compared to the mass of the Earth that all the energy in the gravitational interaction comes back to the object, so, when a particle returns to its original possition (let's said it the zero height), all the potential energy is converted into kinetic energy.

This is not the case if we calculate the G.P.E. between two bodies with a mass of the same order of magnitude.
 
  • #5
donaldparida said:
What is the need of introducing the concept of gravitational potential energy in physics? Can't we simply say that when an object is lifted up it falls down because of the force of gravity acting on it instead of saying that it has G.P.E and so it is falls down?

Let me give an example where GPE helps you where Force is very inconvenient. A trolley rolls down a frictionless ramp that has a wavy profile (like some children's slides). You want to know its speed at the bottom.
To work it out using forces you need to calculate the component of gravity that's acting down the variable slope at every point and to integrate the acceleration over the whole trip.
Using GPE considerations, all you need to do is to equate the KE at the bottom with the lost GPE.
Half m vsquared = mgh
Solve for v and you're done. No calculus. Just two lines of working.
 
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What is the need for introducing the concept of G.P.E?

The concept of G.P.E, or gravitational potential energy, is essential in understanding the behavior of objects in the presence of gravitational force. It helps explain the relationship between an object's position and its potential to do work.

How does G.P.E relate to the law of conservation of energy?

According to the law of conservation of energy, energy cannot be created or destroyed, but it can be transferred from one form to another. G.P.E is a form of potential energy that can be converted into other forms, such as kinetic energy, and vice versa.

Why is it important to know an object's G.P.E?

Knowing an object's G.P.E is crucial in various real-life scenarios, such as calculating the energy required to lift an object to a certain height or predicting the potential energy of an object in a given situation. It also helps in understanding the stability and equilibrium of objects in the presence of gravity.

What is the formula for calculating G.P.E?

The formula for calculating G.P.E is G.P.E = mgh, where m is the mass of the object, g is the gravitational acceleration, and h is the height of the object from a reference point. This formula is derived from the work-energy theorem, where work is the product of force and displacement.

Can G.P.E be negative?

Yes, G.P.E can be negative. This happens when an object is below the reference point, resulting in a negative value for h. In this case, the potential energy is considered to be negative, indicating that the object is in a lower potential energy state compared to the reference point.

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