Discussion

Water flows into a tank 200 m × 150 m through a rectangular pipe 1.5 m × 1.25 m @ 20 kmph. In what time (in minutes) will the water rise by 2 meters?

Answer: D

Work out the water needed and the rate at which it arrives.

\[ V = 200 \times 150 \times 2 = 60{,}000 \text{ m}^{3} \]

\[ \text{pipe cross-section} = 1.5 \times 1.25 = 1.875 \text{ m}^{2} \]

\[ \text{flow} = 1.875 \times 20{,}000 = 37{,}500 \text{ m}^{3}\text{/h} \]

\[ t = \frac{60{,}000}{37{,}500} = 1.6 \text{ h} = 96 \text{ minutes} \]

The speed of 20 kmph becomes 20,000 metres per hour, which is the length of water column delivered each hour.

No comment is present. Be the first to comment.

Loading…