It is required to fix a pipe such that water flowing through it at a s

1.	It is required to fix a pipe such that water flowing through it at a speed of 7 metres per minute fills a tank of capacity 440 cubic metres in 10 minutes. The inner radius of the pipe should be: (a) √2 m (b) 2 m (c) \(\frac12\) m (d) \(\frac1{\sqrt2}\) m
Answer» (a) \(\sqrt2\) m Let the inner radius of pipe be r m. Then, 440 = \(\frac{22}{7}\times{r}^2\times7\times10\) ⇒ r² = \(\frac{440}{22\times10} = 2\) ⇒ r = \(\sqrt2\) m.

It is required to fix a pipe such that water flowing through it at a speed of 7 metres per minute fills a tank of capacity 440 cubic metres in 10 minutes. The inner radius of the pipe should be: (a) √2 m (b) 2 m (c) \(\frac12\) m (d) \(\frac1{\sqrt2}\) m

Answer»

(a) \(\sqrt2\) m

Let the inner radius of pipe be r m.

Then, 440 = \(\frac{22}{7}\times{r}^2\times7\times10\)

⇒ r² = \(\frac{440}{22\times10} = 2\) ⇒ r = \(\sqrt2\) m.