JEE Mains · Physics · STD 12 - Atoms
- JEE Mains 2019
- Medium
- MCQ
A particle \(P\) is formed due to a completely inelastic collision of particles \(x\) and \(y\) having de -Broglie wavelengths \({\lambda _x}\) and \({\lambda _y}\) respectively. If \(x\) and \(y\) were moving in opposite directions, then the de -Broglie wavelength of \(P\) is
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Answer & Solution
Correct Answer
(C) \(\frac{{{\lambda _x}{\lambda _y}}}{{\left| {{\lambda _x} - {\lambda _y}} \right|}}\)
Step-by-step Solution
Detailed explanation
Conservation of momentum
\({\overrightarrow {\text{p}} _x} + {\overrightarrow {\text{p}} _y} = {\overrightarrow {\text{p}} _{{\text{final}}}}\)
\(\mathrm{m}_{\mathrm{x}} \mathrm{V}_{\mathrm{x}}-\mathrm{m}_{\mathrm{y}} \mathrm{V}_{\mathrm{y}}=\left(\mathrm{m}_{\mathrm{x}}+\mathrm{m}_{\mathrm{y}}\right) \mathrm{V}\)
\(\frac{\mathrm{h}}{\lambda_{\mathrm{x}}}-\frac{\mathrm{h}}{\lambda_{\mathrm{y}}}=\frac{\mathrm{h}}{\lambda}\)
\(\Rightarrow \lambda=\frac{\lambda_{x} \lambda_{y}}{\left|\lambda_{x}-\lambda_{y}\right|}\)
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