state and prove the conservation theory of energy for a free falling body
Answers
In other words, we can say that energy can neither be created nor destroyed. In the case of a freely falling body, it is the mechanical energy of the system that is conserved. Mechanical energy (E) is the sum of the potential energy (U) and the kinetic energy (K) of the freely falling body. Therefore, E=K+U=constant.
Answer:
Law of conservation of energy states that:−
Energy can neither be created nor be destroyed.
Energy transforms from one form to another form and, potential energy+ kinetic energy= constant
Proof:−
At point A
K.E=0m/s
P.E=mgh
P.E=mgh
At point B,
K.E.,
2gh=V
2
−O
2
V
2
=2gx
K.E=
2
1
mV
2
K.E=
2
1
m.2gx
K.E=mgx-----------------------------(1)
P.E=mgh
P.E=m.g.(h−x)
P.E=mgh−mgx---------------------(2)
from(1) and (2)
K.E+P.E constant
mgx+mgh−mgx=mgh
mgh=mgh
At point C,
P.E=0
2gh=v
2
−u
2
( initial velocity =0 m/s)
2gh=v
2
K.E=
2
1
.m.v
K.E=
2
1
.m.2gh
K.E=mgh
Thus, in all the points the energy is same
Explanation: