Mathematics

Mathematics

Problem

A cylindrical tank with radius 2 2\,m is being filled with water at a constant rate of 5 5\,m3^{3}/min. Calculate the instantaneous rate of increase of the water height, dhdt\dfrac{dh}{dt}, in m/min.
Intuitive explanation

The key is connecting the volume formula for a cylinder to how fast the height changes. Since V=πr2hV = \pi r^2 h and the radius stays constant at 2 m, you can differentiate both sides with respect to time to relate the rate water is being added (dVdt\frac{dV}{dt}) to the rate the height rises (dhdt\frac{dh}{dt}). This is a classic related rates problem where a constant input rate translates into a constant height-change rate.

Intuitive explanation

The key is connecting the volume formula for a cylinder to how fast the height changes. Since V=πr2hV = \pi r^2 h and the radius stays constant at 2 m, you can differentiate both sides with respect to time to relate the rate water is being added (dVdt\frac{dV}{dt}) to the rate the height rises (dhdt\frac{dh}{dt}). This is a classic related rates problem where a constant input rate translates into a constant height-change rate.

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