A liquid is flowing through a horizontal channel. The speed of flow (v) depends on height (y) from the floor as `v=v_(0)[2((y)/(h))-((y)/(h))^(2)]`.Where h is the height of liquid in the channel and `v_(0)` is the speed of the top layer. Coefficient of viscosity is `eta`. Calculate the shear stress that the liquid exerts on the floor.