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A rocket is fired upward from the earth's surface such that it creates an acceleration of $19.6 ms^{-2}$. If after 5 s, its engine is switched off, the maximum height of the rocket from earth's surface would be
Explanation
Velocity when the engine is switched off $v = 19.6 \times 5 = 98 ms^{-1}$ $h_{max} = h_{1} + h_{2}$ where $h_{1} = \frac{1}{2}a t^{2}$&$h_{2} = v^{2}/2a$ $h_{max} = \frac{1}{2} \times 19.6 \times 5 \times 5 + (98 \times 98)/(2 \times 9.8) = 735 m$