- #1
UrbanXrisis
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is mechanical energy conservative?
Is mechanical energy conservative?
- Thread starter UrbanXrisis
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It is the sum of potential and kinetic energies. In summary, the mechanical energy of a system is sometimes conserved, depending on the presence of friction. In cases where there is no friction, such as a block sliding down a frictionless incline, mechanical energy is conserved. However, when there is friction, mechanical energy is not conserved. It is important to note that mechanical energy itself is not a force, but rather a classification of energies within a system.
- #2
arildno
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No, the mechanical energy of a system might, occasionally be conserved; "conservative"/non-conservative is a way to classify FORCES.
- #3
Doc Al
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I assume you mean: Is mechanical energy conserved? Answer: Sometimes! 
For example: A block sliding down a frictionless incline--mechanical energy (PE + KE) is conserved; but introduce friction, then mechanical energy is not conserved.
Did you have a particular situation in mind?
For example: A block sliding down a frictionless incline--mechanical energy (PE + KE) is conserved; but introduce friction, then mechanical energy is not conserved.
Did you have a particular situation in mind?
- #4
UrbanXrisis
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sliding a block on a flat table. I saw that there wasn't a change in Kinetic Energy. So, that means energy is not conserved. I know that the friction force is non-conservative but I wasn't sure about the mechanical energy.
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Doc Al
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Why would seeing the KE not change lead you to think that energy was not conserved?UrbanXrisis said:
Mechanical energy is not a force.
FAQ: Is mechanical energy conservative?
What is mechanical energy?
Mechanical energy is the energy that an object possesses due to its motion or position. It can be either kinetic energy, which is the energy of motion, or potential energy, which is the energy that an object has due to its position or state.
What does it mean for mechanical energy to be conservative?
A conservative mechanical energy system is one in which the total energy is constant and can be converted between kinetic and potential energy without any losses. This means that the system does not dissipate or gain energy, and the total energy is conserved.
How can we determine if mechanical energy is conserved in a system?
To determine if mechanical energy is conserved in a system, we can use the law of conservation of energy, which states that energy cannot be created or destroyed, only transferred or converted. This means that if there are no external forces acting on the system, the total mechanical energy will remain constant.
What are some examples of mechanical energy being conserved?
One example of mechanical energy being conserved is a pendulum swinging back and forth. The potential energy at the highest point is converted into kinetic energy as the pendulum swings down, and then back into potential energy as it swings back up. Another example is a roller coaster, where the potential energy at the top of the hill is converted into kinetic energy as it goes down, and then back into potential energy as it goes up the next hill.
Can mechanical energy ever be non-conserved?
Yes, mechanical energy can be non-conserved in systems where there is friction or other external forces acting on the objects. These external forces can cause the energy to be dissipated or converted into other forms, such as heat or sound, resulting in a decrease in the total mechanical energy of the system.