Answer:
V = 14 m/s
Step-by-step explanation:
[tex]E = MV^2 ÷ 2 + mgh \\ \\ 4900 = 20V^2 ÷ 2 + 20 \times 9.8 \times 15 \\ \\ 4900 = 10V^2 + 2,940\\ \\ 4900 - 2940 = 10V^2 \\ \\ 1960 = 10V^2 \\ \\ V^2 = \frac{1960}{10} \\ \\ V^2 = 196 \\ \\ V = \sqrt{196} \\ \\ V = 14 \: m {s}^{ - 1} [/tex]
