A) \[8\times {{10}^{-3}}\]s
B) \[80\times {{10}^{-3}}s\]
C) \[800\times {{10}^{-3}}s\]
D) \[8\times {{10}^{-4}}s\]
Correct Answer: D
Solution :
\[{{v}^{2}}={{u}^{2}}+2as\Rightarrow {{(9000)}^{2}}-{{(1000)}^{2}}\]\[=2\times a\times 4\] \[\Rightarrow a={{10}^{7}}m/{{s}^{2}}\]Now \[t=\frac{v-u}{a}\] \[\Rightarrow \ t=\frac{9000-1000}{{{10}^{7}}}=8\times {{10}^{-4}}\ sec\]You need to login to perform this action.
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