This figure is not drawn to scale. A rectangular glass tank 70 cm by 57 cm by 46 cm has 2 compartments, Q and R, with a water height of 31 cm in Q and 17 cm in R. A hole in the slider caused water to leak from Q to R. It was found that the water level in both compartments became the same after some time.
- What is the height of water in the tank now?
- It took 112 h for the water in both compartments to reach the same level. Assuming that water leaked at a constant rate, how much water flowed from Q to R in 1 minute? Express your answer to 1 decimal place in cm³.
(a)
Volume of water in Compartment Q
= 25 x 31 x 57
= 44175 cm
3 Length of Compartment R
= 70 - 25
= 45 cm
Volume of the water in Compartment R
= 45 x 57 x 17
= 43605 cm
3 Total volume of water
= 44175 + 43605
= 87780 cm
3 Base area of the glass tank
= 70 x 57
= 3990 cm
2 Height of water
= 87780 ÷ 3990
= 22 cm
(b)
1
12 h = 90 min
Drop in the height of Compartment Q
= 31 - 22
= 9 cm
Drop in the volume of Compartment Q
= 57 x 25 x 9
= 12825 cm
3 Volume of water flowed from Q to R in 1 minute
= 12825 ÷ 90
≈ 142.5 cm
3 Answer(s): (a) 22 cm; (b) 142.5 cm
3