How does KE get changed into internal energy?

In summary, the conversation discusses the transformation of macroscopic kinetic energy into internal energy through different scenarios such as a car bumping into a trash can and friction changing the KE of a body into internal energy. The participants also question how this transformation happens and discuss possible explanations, such as the compression of a spring and the scattering of energy at the atomic/molecular level.
  • #1
something_about
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hello

How does macroscopic kinetic energy KE get transformed into internal energy?

Car bumps into trash can and small dent is made in the car.Dent is caused
by force from trash can over certain distance (i.e. car gave part of its KE to trash can and trash can gave part of its KE back to car, which transformed it into internal energy)?

How did this transformation happen?I know if we try to deform a body a net force is created on atomic level that resists external force trying to deform a body even more.
But if I'm not mistaken that act alone doesn't change internal energy?
So what does?

Same question for situation when friction changes KE of a body into internal energy. How exactly do molecules gain speed and thus gain internal kinetic energy?

thank you
 
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  • #2
On the dent part, think of the analogy where the object being hit has a spring protruding and a ratchet mechanism to hold the spring at any compressed length. As the car hits the spring and compresses it, the spring ratchets in some and then stays at some compressed length. The conversion in energy has been from the car's drop in KE to the spring's increased PE. The increased PE of the spring can be considered internal energy for the thing that the car ran into.
 
  • #3
hi

And how does friction get transformed into thermal energy?
 
  • #4
The directed energy of an impact can become randomized at the atomic/molecular level by scattering.
 

FAQ: How does KE get changed into internal energy?

1. How is kinetic energy converted into internal energy?

When an object is in motion, it possesses kinetic energy due to its velocity. This kinetic energy can be transferred to the particles within the object, causing them to vibrate faster and increase their internal energy. This transfer of energy can happen through collisions or friction.

2. What factors affect the conversion of KE into internal energy?

The amount of kinetic energy that is converted into internal energy depends on the material and structure of the object, as well as the speed and direction of the motion. The type of surface and the force of friction also play a role in the conversion process.

3. How does temperature relate to the conversion of KE into internal energy?

As kinetic energy is converted into internal energy, the temperature of the object increases. This is because the faster and more intense the vibrations of the particles, the higher the temperature. In other words, an increase in internal energy leads to an increase in temperature.

4. Can KE be converted into internal energy without any loss?

No, according to the law of conservation of energy, energy cannot be created or destroyed. Therefore, when kinetic energy is converted into internal energy, there will always be some loss of energy in the form of heat or sound.

5. How does the conversion of KE into internal energy impact the overall energy of a system?

The conversion of kinetic energy into internal energy does not change the overall energy of a closed system. This means that while the kinetic energy may decrease, the internal energy will increase by an equal amount, keeping the total energy of the system constant.

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