Newton's third law and energy transfer

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SUMMARY

This discussion clarifies the relationship between Newton's third law and energy transfer. Newton's third law states that for every action, there is an equal and opposite reaction, which pertains to forces rather than energy. When a force is applied to an object, such as pushing a box, energy is transferred to the object, but the object does not "give back" energy; instead, it absorbs energy through deformation or heat. Additionally, when an object is dropped, it converts potential energy into kinetic energy upon impact, with energy dissipating as heat and sound.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Basic concepts of energy types: potential and kinetic energy
  • Knowledge of work definition: force acting over a distance
  • Familiarity with energy transfer mechanisms in physical systems
NEXT STEPS
  • Study the principles of energy conservation in mechanical systems
  • Explore the concept of work-energy theorem in physics
  • Investigate the effects of friction on energy transfer
  • Learn about deformation and heat generation in materials under force
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Students of physics, educators explaining energy concepts, and anyone interested in understanding the dynamics of force and energy transfer in physical systems.

Berney123
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If Newtons third law says there is an equal and opposite reaction how can there be energy transfer.
For example if I push a box and give it 1000 joules of energy wouldn't it "give back" the energy. Also does an object have to be moved for it to gain energy, if I were to punch a book many times would it gain energy or is it just giving back the energy becausE of Newtons third law. And if I drop a ball from a height of 10 feet wouldn't it gain energy after it hits the ground because I am supplying it with potential energy than it is converted into kinetic as it falls once it hits the ground the energy is transferred into the ground and then back into the ball therefore giving the ball more energy than when it started. Please correct me if I am wrong
 
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Recall the definition of work, which is force acting over a distance; the direction of the force matters. If I push a box 1m along the X axis, with a force of 1N, I have expended 1J of energy, because the displacement is in the direction of the force. The box on the other hand absorbed 1J or energy(or rather friction did), as the force it applied was opposite the displacement.
 
Welcome to PF!
Berney123 said:
If Newtons third law says there is an equal and opposite reaction how can there be energy transfer.
For example if I push a box and give it 1000 joules of energy wouldn't it "give back" the energy.
Newton's 3rd law is about force not energy. If you apply a force to a box, it applies a force back at you.
Also does an object have to be moved for it to gain energy, if I were to punch a book many times would it gain energy or is it just giving back the energy becausE of Newtons third law.
There are different kinds of energy. If you punch a book a bunch of times and it doesn't move, it will absorb energy due to deformation and heat up.
And if I drop a ball from a height of 10 feet wouldn't it gain energy after it hits the ground...
It loses potential energy and gains kinetic energy until it hits the ground. Then it loses the (linear) kinetic energy too, converting it to heat and sound.
 
In my first question you said that the box applies a force back to you, but doesn't it take energy to supply a force. And in the second question about punching the book, would the same outcome happen to any object punched repeteadly.
 
Berney123 said:
In my first question you said that the box applies a force back to you, but doesn't it take energy to supply a force.
...
No. It does not take energy to apply a force.
 

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