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Question
Consider a one-dimensional motion of a particle with total energy E. There are four regions A, B, C and D in which the relation between potential energy V, kinetic energy (K) and total energy E is as given below:
Region A : V > E
Region B : V < E
Region C : K > E
Region D : V > K
State with reason in each case whether a particle can be found in the given region or not.
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Solution
We know that
Total energy E = PE + KE
⇒ E = V + K ......(i)
For region A Given, V > E, From equation (i)
K = E – V
As V > E ⇒ E – V < 0
Hence, K < 0, this is not possible.
For region B Given, V < E ⇒ E – V > 0
This is possible because total energy can be greater than PE(V)
For region C Given, K > E ⇒ K – E > 0
From equation (i) PE = V = E – K < 0
This is possible because PE can be negative.
For region D Given, V > K
This is possible because for a system PE (V) may be greater than KE (K).
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