How is the amount of energy dissipated by friction calculated?

In summary, the conversation discusses finding the equation for the amount of energy dissipated by friction when a block stops, and suggests using the initial and final potential and kinetic energy to calculate the energy lost. It also mentions that total energy is always conserved, and any energy lost due to friction is compensated for by other forms of energy.
  • #1
cmed07
4
0
I need help figuring out the equation for E :

Find the amount of energy E dissipated by friction by the time the block stops. Express your answer in terms of some or all the variables m, v, and h and any appropriate constants.
 
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  • #2
cmed07 said:
I need help figuring out the equation for E :

Find the amount of energy E dissipated by friction by the time the block stops. Express your answer in terms of some or all the variables m, v, and h and any appropriate constants.
You'll ned to furnish a sketch or more info, and an attempt at a solution, before we can help...
 
  • #3
Since the problem states "by the time the block stops." we can assume the final energy is purely potential energy.

So one possibility could be finding the initial potential and kinetic energy and subtracting the final potential energy from those.

KEi+PEi-PEf=Energy lost

Then plug in your variables for KE and PE

This is assuming energy is not being lost due to any force other than friction.
 
  • #4
Sovos said:
Since the problem states "by the time the block stops." we can assume the final energy is purely potential energy.

So one possibility could be finding the initial potential and kinetic energy and subtracting the final potential energy from those.

KEi+PEi-PEf=Energy lost

Then plug in your variables for KE and PE

This is assuming energy is not being lost due to any force other than friction.
Yes, looks very good! You even got the plus and minus signs correct :cool: Now just adapt that to your given problem.
 
  • #5
Sovos said:
Since the problem states "by the time the block stops." we can assume the final energy is purely potential energy.

So one possibility could be finding the initial potential and kinetic energy and subtracting the final potential energy from those.

KEi+PEi-PEf=Energy lost

Then plug in your variables for KE and PE

This is assuming energy is not being lost due to any force other than friction.

Thanks! This helped me a lot :)
 
  • #6
cmed07 said:
Thanks! This helped me a lot :)
OK, but just remember (because I forgot!) that total energy can neither be gained nor lost...it is always conserved. What energy is lost due to friction is compensated for by an increase in heat, sound, and other forms of energy.
 

1. What is energy dissipation?

Energy dissipation is the process by which energy is converted into a form that cannot be used for useful work. In the case of friction, energy is dissipated as heat.

2. How does friction cause energy dissipation?

Friction occurs when two surfaces come into contact and rub against each other. This rubbing motion causes resistance, which converts the kinetic energy of motion into heat energy, resulting in energy dissipation.

3. What factors affect the amount of energy dissipated by friction?

The amount of energy dissipated by friction depends on the force of the objects in contact, the roughness of the surfaces, and the speed at which they are moving. Other factors such as temperature and lubrication can also impact the amount of energy dissipated.

4. Why is energy dissipation important to understand?

Energy dissipation is important because it affects the efficiency of systems and processes. In some cases, it is desirable to minimize energy dissipation to maximize efficiency and reduce energy waste, while in others, it is necessary for safety and control.

5. Can energy dissipation be beneficial?

Yes, energy dissipation can be beneficial in some cases. For example, in braking systems, friction is necessary to dissipate kinetic energy and slow down a moving object. In addition, friction can also be used to generate electricity in systems such as regenerative braking in hybrid vehicles.

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