A) 1.5 cm
B) 1.0 cm
C) 3.0 cm
D) 2.0 cm
Correct Answer: B
Solution :
Let initial velocity of the bullet = u After penetrating 3 cm its velocity becomes \[\frac{u}{2}\] From \[{{v}^{2}}={{u}^{2}}-2as\] \[{{\left( \frac{u}{2} \right)}^{2}}={{u}^{2}}-2a\,(3)\] Þ \[6a=\frac{3{{u}^{2}}}{4}\] Þ \[a=\frac{{{u}^{2}}}{8}\] Let further it will penetrate through distance x and stops at point C. For distance BC, \[v=0,\,u=u/2,\,s=x,\,a={{u}^{2}}/8\] From \[{{v}^{2}}={{u}^{2}}-2as\]Þ\[0={{\left( \frac{u}{2} \right)}^{2}}-2\left( \frac{{{u}^{2}}}{8} \right)\,.\,x\]Þ\[x=1\] cm.You need to login to perform this action.
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