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Read the posting on Sarin learns rate of change in school (Math Concept) to learn about concept of rate of change.
You can read the posting on Sarin learns Perimeter, Area and Volume in school(Math Concept) to learn the concept of volume.
Upper primary school mathematics question UPQ219
Two rectangular tanks A and B measures 40 cm by 20 cm by 40 cm and 50 cm by40 cmby 45 cm respectively. Water is being filled by Tap P and Q at a rate of 1.2 litres/min and 5 litres/min in Tank A and Tank B respectively. At 8 a.m., Tap P was turned on first.
(a) What is the height of the water level in Tank A after 10 minutes?
(b) At 8.10 a.m., Tap Q was then turned on. At what time will the height of the water level in both tanks equal?
The flow rate of tape P = 1.2 l/min
The volume of water in tank A after 10 minutes = 1.2 × 10 = 12 l
The height of the Water level in tank A after 10 minutes = 12000 ÷ 40 ÷ 20 = 15 cm
The flow rate of tape Q = 5 l/min
The height of the water level in tank B after 10 minutes = 50000 ÷ 50 ÷ 40 = 25 cm
The rate of change of height in tank A = 15 ÷ 10 = 1.5 cm/min
The rate of change of height in tanks B = 25 ÷ 10 = 2.5 cm/min
The different in height in the two tanks = 2.5 – 1.5 = 1 cm/min
Tank A had 15 cm height of water when tank B start to fill
The time require to have same height level in the two tanks = 15 ÷ 1 = 15 min
At 8.25 a.m., both tanks had same water height level.