Explanation:
[tex]kinetic \: energy= \frac{1}{2} m {v}^{2} [/tex]
[tex]2 \times {10}^{5} = \frac{1}{2} 1000 {v}^{2} [/tex]
[tex]2 \times {10}^{5} = 500 {v}^{2} [/tex]
[tex] \frac{2 \times {10}^{5} }{500} = {v}^{2} [/tex]
[tex] {v}^{2} = 400[/tex]
[tex]v = 20[/tex]
