Question

At the mouth of the tap,the area of cross section is 2 cm^2 and the speed of water is 3m/s.The area of cross section of the water column 80 cm below the tap is

Answer 1

1.2cm³

Explanation:

Given,

h = 80cm = 0.8m, u = 3m/s, area(A1) = 2cm³

Let, water velocity below 80cm = v

we know that,

v² = u²+2gs

v² = 3³+2x10x0.8 (g=10m/s²)

v² = 9+16 = 25

v = 5m/s

Now,

A1v1 = A2v2

2cm³x3m/s = A2x5m/s

6cm³ = A2 x 5

A2 = 6/5 cm³ = 1.2cm³