Question

plz ans this
give me the D in m not in cm

Answer 1

Given,

Level of tank in half  hour = 3.15 m

Level of  tank in  one hour  = 2× 3.15 = 6.3 m

Radius of tank = 40cm = 40/100 m = 4/10 m

Volume of  water  in tank in one  hour  V₁= π(4/10)²×6.3

Again,

Speed  of water  = 2.52 km/hr =2520km/hr. It means that  water   travels 2520 km in hour  in pipe.

Let the radius  of  pipe  be  r

Volume  of  water  through pipe one  hour ,V₂ = πr²×2520

Now,

V₁ = V₂

π(4/10)²×6.3 =  πr²×2520

16/100 × 6.3 = r² × 2520

r² = 1/2500

r = 1/50 m

r = 100/50 = 2 cm

Radius  of  pipe   = 2cm

Diameter  of pipe  = 4 cm

Answer 2

Convert all to m:

Radius = 40 cm = 0.4m

Speed of the pipe = 2.52 km/h = 2520 m/h

Find the volume of the water in the tank after 1/2 hour:

Volume = πr²h

Volume = π(0.4)²(3.15) = 0.504π m³

Find the volume of the water in the tank after 1 hour:

1/2 hour = 0.504π m³

1 hour = 0.504π x 2 = 1.008π m³

Find the amount of water coming out from the pipe in 1 hour

Speed = 2520 m/h

Area of the pipe = πr²

Amount of water = 2520πr² m³

Find radius:

2520πr²=  1.008π

r² = 1.008π ÷ 2520π

r² = 0.0004

r = √0.004

r = 0.02 m

Find diameter:

Diameter = radius x 2

Diameter = 0.02 x 2 = 0.04 m

Answer: The diameter is 0.04 m