If the water falls from a dam into a turbine wheel $19.6\, m$ below, then the velocity of water at the turbine is ............. $\mathrm{m/s}$ $(g = 9.8\,m/{s^2})$
If the water falls from a dam into a turbine wheel $19.6\, m$ below, then the velocity of water at the turbine is ............. $\mathrm{m/s}$ $(g = 9.8\,m/{s^2})$
$9.8$
$19.6$
$39.2$
$98$
If the water falls from a dam into a turbine wheel $19.6\, m$ below, then the velocity of water at the turbine is ............. $\mathrm{m/s}$ $(g = 9.8\,m/{s^2})$
Potential energy of water = kinetic energy at turbine
$mgh = \frac{1}{2}m{v^2}$$⇒$$v = \sqrt {2gh} = \sqrt {2 \times 9.8 \times 19.6} = 19.6\,m/s$
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