Can energy only be transferred if there is motion.

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Energy transfer requires motion, as demonstrated by the example of punching an object that does not move; in this case, no energy is transferred to the object. The opposing force from the Earth prevents any energy gain, resulting in zero net energy change. While deformation and heat can occur, they are minimal and not related to the object's overall motion. Kinetic energy is specifically linked to movement, meaning that without displacement, energy transfer is negligible. Therefore, consistent force applied to a stationary object does not result in mass gain according to the principles of e=mc².
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For example if I punch an object and it doesn't move, am I giving it energy, if so after doing that billions of times wouldn't it gain mass because e=mc2.
 
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For example if I punch an object and it doesn't move, am I giving it energy
You are not. The Earth (or whatever prevents the object from moving) pushes against the object in the opposite direction, and the energy gained by the object is 0. If you take deformations into account, you could heat it a tiny bit, but that is not related to the motion of the whole object.
 
Berney123 said:
For example if I punch an object and it doesn't move, am I giving it energy, if so after doing that billions of times wouldn't it gain mass because e=mc2.
Depends I guess. If you are hammering iron to make a sword you transfer quite a lot of energy into unmovable object.
 
Kinetic energy is directly tied to motion, so in that sense, no. However, there are many other types of energy, such as the deformation that has already been alluded to. When you punch a box or you hit a sword with a hammer, however, the give the slightest amount, and in that moment apply a great deal of force, absorbing energy in the form of heat and deformation. The kinetic energy of the object as a whole doesn't change though.
 
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