Final answer:
The dynamic viscosity of the oil is calculated using the relationship between the force, the velocity of the moving plate, the area of the plate, and the thickness of the oil film. By substituting the given values into the Newton's law of viscosity equation, the dynamic viscosity is found to be 3.92 poise.
Step-by-step explanation:
The student is looking to determine the dynamic viscosity of the oil in poise using the given values for force, velocity, and dimensions of the plates. The relevant equation, derived from Newton's law of viscosity, is F = η(Av/L), where F is the force, η (eta) is the dynamic viscosity, A is the area of the plate in contact with the oil, v is the velocity of the plate, and L is the separation between the plates (thickness of the oil film).
Substituting given values into the equation:
We can rearrange the formula to solve for η:
η = F * L / (A * v)
Substitute the known values:
η = 98.1 N * 0.0125 m / (0.36 m² * 2.5 m/s)
Calculating this gives the dynamic viscosity of the oil in Ns/m², which can be converted to poise by multiplying by 10 since 1 poise = 0.1 Ns/m².
Therefore, the dynamic viscosity of the oil is 3.92 poise, which corresponds to option a).