1. The problem statement, all variables and given/known data A piston 10 is coaxially in diameter moves within a cylinder whose inner diameter is 10.006 in; The annular space between piston and cylinder is filled with oil having a kinematic viscosity is 0.004 feet ^ 2 / s and specific gravity of 0.85 If the piston makes its way with a speed of 30 ft / min and the length of the piston within the cylinder is 10 feet, calculate the shear force and the friction opposing the motion of the piston 2. Relevant equations (tangencial force) / area = (dynamic viscosity) (velocity/space betwteen the two surfaces) 3. The attempt at a solution I can know the dynamic viscosity of the equation kinematic viscosity = dynamic viscosity/density and the density it can be known from the specific gravit. So if I draw a Diagram of piston, I have two tangent forces and the weight. But I know that (tangencial force) / area = (dynamic viscosity) (velocity/space betwteen the two surfaces) and the area of contact it can be calculated from 2(pi)(radio) (Lenght)???