The figure shows an empty rectangular tank with a capacity of 52 ℓ. The tank has a height of 20 cm. Tap V filled the tank at a rate of 3.2 ℓ per minute. Tap W drained water from the tank at a rate of 1.6 ℓ per minute. Both taps were turned on for 18 minutes and then turned off.
- What is the base area of the tank?
- After both taps were turned off, how much more water is needed to fill the tank completely? Give your answer in litres.
(a)
1 ℓ = 1000 mℓ
52 ℓ = 52 x 1000 = 52000 mℓ
Base area of the tank
=
Volumeheight =
5200020 = 2600 cm
2 (b)
Volume of water that filled the tank per minute when both taps were turned on
= 3.2 - 1.6
= 1.6 ℓ
Volume of water that filled the tank in 18 minutes when both taps were turned on
= 18 x 1.6
= 28.8 ℓ
Volume of water needed to fill the tank
= 52 - 28.8
= 23.2 ℓ
Answer(s): (a) 2600 cm
2; (b) 23.2 ℓ