An empty cylindrical tank is 140 cm in diameter. If 200 litres of water was poured into the tank. Calculate, correct to the nearest centimeter, the height of the water in the tank. (\(Take \pi = \frac{22}{7})\)
A.
91cm
B.
7cm
C.
13cm
D.
57cm
Correct answer is C
given that diameter = 140cm ⇒radius = 70cm, volume of cylinder = 200litres = \(200,000cm^3\)
volume of cylinder = base area times height = \(\pi r^2h\)
\( 200,000cm^3 = \frac{22}{7} \times 70 \times 70 \times h\)
\(200,000 = \frac{107,800h}{7}\)
cross multiply
1,400,000 = 107,800h
\( h = \frac{1,400,000}{107,800}\)
= 13cm (to the nearest cm).
