An ideal liquid of density `rho` is pushed with velocity v through the central limb of the tube shown in fig. What force does the liquid exert on the tube? The cross sectional areas of the three limbs are equal to A each. Assume stream-line flow.

Options

A. `9/8 rho Av^(2)`
B. `5/4 rho Av^(2)`
C. `3/2 rho Av^(2)`
D. `rho Av^(2)`

Answer

B

Explanation

Velocity of liquid through inclined limbs = `(v)/(2)`
Rate of change of momentum of the liquid is
`=rho Av^(2)+2[rhoA((v)/(2))^(2) cos 60^(@)]=5/4 rho Av^(2)`.