Question

A rectangular water tank measuring 8mx6mx 4 cm is filled from a pipe of cross sectional area 1.5 cm², the water emerging at 10 m/s. How long does it take to fill the tank?

Answer 1

Time taken to fill the tank

= `"Volume of the tank"/"Volume of water flown in it 1 s"`

Volume of tank
= 800 x 600 x 4cm³
Volume of water flown out of the pipe in 1 s
= Area of cross section x Rate of flow
= 1.5 x 10(m/s)
= 1.5 x 10 x 100(cm/s)
= 1500cm
∴ The time taken to fill the tank

= `(800 xx 600 xx 4)/(1500)`
= 1280s
∴ The time taken to fill the tank is 1280s.