Question

A water pipe with diameter of 5.0 cm is connected to another pipe of diameter 2.5 cm. How would the speeds of the water flow compare?

Answer 1

d₁ = 5 cm = d₂ = 2 .5 cm

∵ A₁ v₁ = A₂ v₂

∴ `v_1/v_2 = A_2/A_1 = (pir_2^2)/ (pi r_1^2)`

`= ((d_2//2) /( d_1//2))^2 = (d_2/d_1)^2`

∴ `v_1/v_2 = (2.5/5)^2`

`= (1/2)^2`

`= 1/4`