JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
A bullet looses \({\left( {\frac{1}{n}} \right)^{th}}\) of its velocity passing through one plank. The number of such planks that are required to stop the bullet can be
- A \(\frac{{{n^2}}}{{2n - 1}}\)
- B \(\frac{{2{n^2}}}{{n - 1}}\)
- C infinite
- D \(n\)
Answer & Solution
Correct Answer
(A) \(\frac{{{n^2}}}{{2n - 1}}\)
Step-by-step Solution
Detailed explanation
\begin{array}{l} \left( a \right)\,\,\,\,\,\,Let\,u\,be\,the\,initial\,velocity\,of\,the\,bullet\,of\,\\ \,\,\,\,\,\,\,\,\,\,\,\,mass\,m.\\ \,\,\,\,\,\,\,\,\,\,\,\,After{\rm{ passing}}\,through\,a\,plank\,of\,width\,x,\\ \,\,\,\,\,\,\,\,\,\,\,\,its\,velocity\,decreases\,to\,v.\\…
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