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Consider an object dropped from a height h above the Earth's surface. Observe the motion from the following two reference frames :-
1. The frame fixed to the Earth's surface :-
Initially,
Potential energy of the object = [tex]mgh[/tex]
Kinetic energy of the object = [tex]0[/tex]
Finally,
Potential energy of the object = [tex]0[/tex]
Kinetic energy of the object = [tex]mgh[/tex]
2. A frame moving towards the Earth's surface at a constant speed of [tex]\sqrt{2gh}[/tex] :-
Initially,
Potential energy of the object = [tex]mgh[/tex]
Kinetic energy of the object = [tex]\frac{1}{2} m(\sqrt{2gh})^2[/tex] = [tex]mgh[/tex]
Finally,
Potential energy of the object = [tex]0[/tex]
Kinetic energy of the object = [tex]0[/tex]
It appears that in the second case, the energy is not conserved. What's the flaw in the above reasoning?
1. The frame fixed to the Earth's surface :-
Initially,
Potential energy of the object = [tex]mgh[/tex]
Kinetic energy of the object = [tex]0[/tex]
Finally,
Potential energy of the object = [tex]0[/tex]
Kinetic energy of the object = [tex]mgh[/tex]
2. A frame moving towards the Earth's surface at a constant speed of [tex]\sqrt{2gh}[/tex] :-
Initially,
Potential energy of the object = [tex]mgh[/tex]
Kinetic energy of the object = [tex]\frac{1}{2} m(\sqrt{2gh})^2[/tex] = [tex]mgh[/tex]
Finally,
Potential energy of the object = [tex]0[/tex]
Kinetic energy of the object = [tex]0[/tex]
It appears that in the second case, the energy is not conserved. What's the flaw in the above reasoning?