Understanding Kinetic Energy: A Beginner's Guide

In summary, when there is friction or inelastic collisions, kinetic energy is not conserved. This is because energy is transferred to the surroundings in the form of heat, sound, etc. Additionally, the work-energy theorem states that the work done on a system is equal to the change in kinetic energy. This means that external forces or torques can change the kinetic energy of a system. For linear motion, this can be calculated using the equation W=\DeltaKE=Fd, and for rotational motion, it is W=\DeltaKE=\tau\theta.
  • #1
ZoeGab
10
0
I feel that I don't comprehend kinetic energy fully. I am trying to figure out under what conditions would kinetic energy not be conserved using prinicples of physics. Can anyone help me understand this better. Please try and put it in laymans terms because this is all new to me. It will not be helpful if I can't understand what you are explaining to me. I really appreciate any help anyone can provide!
 
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  • #2
When you have friction, kinetic energy is not conserved. Some colliding objects don't conserve kinetic energy.
 
  • #3
Also, have another look at the work-energy theorem. It states that the work done will be equal to the change in kinetic energy. If work is done...kinetic energy will change.
 
  • #4
How does this sound? I am not sure if this is correct

kinetic energy can be changed to electrical energy using a generator,
into heat energy using friction or inelastic collisions
into electromagnetic radiation by striking certain crystals,
into potential energy by lifting an object or compressing a gas.
 
  • #5
ZoeGab said:
How does this sound? I am not sure if this is correct

kinetic energy can be changed to electrical energy using a generator,
into heat energy using friction or inelastic collisions
into electromagnetic radiation by striking certain crystals,
into potential energy by lifting an object or compressing a gas.


Well these are true, not sure about the electromagnetic one though since I have not studied much about that.
 
  • #6
KE changes when an external force or torque is applied to a system. W=[tex]\Delta[/tex]KE=Fd for linear motion or =[tex]\tau[/tex][tex]\theta[/tex] for rotational.
 
  • #7
sigmavirus said:
KE changes when an external force or torque is applied to a system. W=[tex]\Delta[/tex]KE=Fd for linear motion or =[tex]\tau[/tex][tex]\theta[/tex] for rotational.

Could you explain this a little further?
 
  • #8
when a force acts on a system, KE is gained or lost (within the system at least, because energy is never destroyed). like friction. energy is lost in the forms of heat, sound, etc. and transferred to the surroundings. If you push an object from rest, exerting a force, it will gain velocity and, thus, KE. Torque is the same concept, but for rotational motion. I don't know how much you know about that, though.
 

1. What is kinetic energy?

Kinetic energy is the energy an object possesses due to its motion. It is a type of energy that can be transferred from one object to another through collisions or interactions.

2. How is kinetic energy calculated?

Kinetic energy is calculated using the formula: KE = 1/2 * m * v^2, where m is the mass of the object and v is its velocity. This means that an object with a larger mass or higher velocity will have a greater kinetic energy.

3. What are some real-life examples of kinetic energy?

Some examples of kinetic energy in everyday life include a moving car, a person running, a ball rolling down a hill, and a pendulum swinging back and forth. Any object in motion has kinetic energy.

4. How is kinetic energy related to potential energy?

Kinetic energy and potential energy are two forms of energy that can be converted into each other. Potential energy is the energy an object has due to its position or state, while kinetic energy is the energy an object has due to its motion. For example, a ball at the top of a hill has potential energy, but as it rolls down the hill, it converts that potential energy into kinetic energy.

5. How does temperature affect kinetic energy?

Temperature is a measure of the average kinetic energy of particles in a substance. As the temperature increases, the particles in a substance move faster and have more kinetic energy. This is why substances typically expand when heated, as the particles are moving more and take up more space.

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