A) 5 m/s
B) 14 m/s
C) 17.5 m/s
D) 10 m/s
Correct Answer: D
Solution :
\[F=\frac{-\partial U\,\hat{i}}{\partial x}\frac{-\partial U\,\hat{j}}{\partial y}\] \[=7\,\hat{i}-24\,\hat{j}\] \[\therefore \,{{a}_{x}}=\frac{{{F}_{x}}}{m}\] \[=\frac{7}{15}=1.4\,m/{{s}^{2}}\], along positive x-axis \[{{a}_{y}}=\frac{{{F}_{y}}}{m}=-\frac{24}{5}\] \[=4.8\,m/{{s}^{2}}\] along negative y-axis \[\therefore \] \[{{v}_{x}}={{a}_{x}}t=1.4\times 2=2.8\,m/s\] and \[{{v}_{y}}=4.8\times 2=9.6\,m/s\] \[\therefore \] \[v=\sqrt{v_{x}^{2}+v_{y}^{2}}=10\,m/s\]
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