# GATE2017 ME-2: 41

For the laminar flow of water over a sphere, the drag coefficient $C_{F}$ is defined as $C_{F}=F/(\rho U^{2} D^{2})$, where $F$ is the drag force, $\rho$ is the fluid density, $U$ is the fluid velocity and $D$ is the diameter of the sphere. The density of water is $1000 kg/m^{3}$. When the diameter of the sphere is $100$ mm and the fluid velocity is $2$ m/s, the drag coefficient is $0.5$. If water now flows over another sphere of diameter $200$ mm under dynamically similar conditions, the drag force (in N) on this sphere is ________.

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## Related questions

A $60$ mm-diameter water jet strikes a plate containing a hole of $40$ mm diameter as shown in the figure. Part of the jet passes through the hole horizontally and the remaining is deflected vertically. The density of water is $1000 kg/m^{3}$. If velocities are as indicated in the figure, the magnitude of horizontal force (in N) required to hold the plate is _________.
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