JEE Mains · Physics · STD 11 - Work,energy,power and collision
- JEE Mains 2021
- Hard
- MCQ
Given below is the plot of a potential energy function \(U(x)\) for a system, in which a particle is in one dimensional motion, while a conservative force \(F(x)\) acts on it. Suppose that \(E_{\text {mech }}=8\, {J}\), the incorrect statement for this system is:
Pick an option to check your answer.
Answer & Solution
Correct Answer
(C) at \(x\,<\,x_{1}\), \(K.E.\) is smallest and the particle is moving at the slowed speed.
Step-by-step Solution
Detailed explanation
Given
\(\left.E_{\text {mech. }}=8\right]\)
\((A)\) at \(x\,>\,x_{4}, \quad U=\) constant \(\left.=6\right]\)
\({K}={E}_{{mech} .}-{U}=2\, {J}=\) constant
\((B)\) at \(x\,<\,x_{1}, \quad U=\) constant \(\left.=8\right]\)
\({K}={E}_{\text {mech. }}-{U}=8-8=0 \,{J}\)
Particle is at rest.
\((C)\) At \(x=x_{2}, U=0 \Rightarrow E_{\text {mech. }}=K=8\) ]
\({KE}\) is greatest, and particle is moving at fastest speed.
\((C)\) \((D)\) At \(\left.x=x_{3}, \quad U=4\right]\)
\({U}+{K} =8\, {J}\)
\({K} =4\, {J}\)
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