The body falls freely from a height of 60 m. At what height from the earth’s surface
The body falls freely from a height of 60 m. At what height from the earth’s surface, the kinetic and potential energies of the body will be the same?
This problem should be considered as a general phenomenon for the free fall of a body from any height.
At the beginning of the fall, the potential energy of the body is maximum E potential = mgh, while the kinetic energy is equal to zero (E kinet = mv² / 2 (the speed at the beginning of the fall is zero)).
At the end of the fall, on the contrary, E potential is equal to zero, E potential is at its maximum.
In this case, the total energy of the body remains unchanged – E total = E potential + E will throw, and it is always equal in its value to E total = E potential maximum at the beginning of the fall (or E will throw maximum at the end of the fall).
As the body falls, a mutual transfer of energies occurs (potential decreases, kinetic increases).
Obviously, their values will equal half of the path covered by the body, regardless of the height from which the body begins to fall (at this moment E potential = (mgh) / 2). The potential energy will be reduced by exactly half.
Consequently, the kinetic exactly at this point will equal the potential, since in total they will represent the same constant value – E total = 0.5 E potential (from the maximum value) + 0.5 E will throw (from the maximum value).
Thus, at a height of 30 meters, the kinetic and potential energies of our body will be the same.
And – wider – for a free fall of a body from any height, its energies will be equal (E potential = E throw) exactly halfway (height) of the fall.