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JEE Mains · Physics · STD 11 - 6. system of particles and rotational motion
A boy of mass \(20\, kg\) is standing on a \(80\, kg\) free to move long cart. There is negligible friction between cart and ground. Initially, the boy is standing \(25\, m\) from a wall. If he walks \(10\, m\) on the cart towards the wall, then the final distance of the boy from the wall will be ........ \(m\)
- A \(15\)
- B \(12.5\)
- C \(15.5\)
- D \(17\)
Answer & Solution
Correct Answer
(D) \(17\)
Step-by-step Solution
Detailed explanation
\begin{array}{l} As\,there\,is\,no\,external\,Force,\,so\,\\ displacement\,oF\,center\,oF\,mass\,oF\\ the\,cart + boy\,system\,parallel\,to\,the\\ surFace\,is\,zero.\\ \Delta {x_{cm}} = \left( {{m_1}\Delta {x_1} + {m_1}\Delta {x_1}} \right)/\left( {{m_1} + {m_2}} \right)\\ 0 =…
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