A) 40 m/s
B) 42 m/s
C) 52 m/s
D) 4m/s
Correct Answer: B
Solution :
\[{{S}_{n}}=u+\frac{a}{2}(2n-1)\] \[12=u+\frac{a}{2}(2\times 3-1)\] ?(i) and \[20=u+\frac{a}{2}(2\times 5-1)\] ?(ii) Subtract Eq. (i) from Eq. (ii) \[8=\frac{a}{2}(9-5)=2a\] \[\Rightarrow \] \[a=4m/{{s}^{2}}\] From Eq. (i) \[12=u+\frac{4}{2}\times 5\] \[u=2\,m/s\] Velocity \[v=u+at=2+4\times 10\] \[=42\,m/s\]You need to login to perform this action.
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