# A tube of length 20 m and radius r m carries a steady flow of a liquid whose density and viscosity are 2 kgm−3 and 1 kgm−1s−1, respectively. The velocity of the fluid at a distance x from the centre of the tube is given as . If the friction force exerted by the liquid on the tube is N, then what is the value of r?

Your question seems to be incomplete with some values missing.

Kindly post it again for us to answer.

Regards

**
**