Question

Motor oil, with a viscosity of 0.25 N ∙ s/m2, is flowing through a tube that has a radius of 3.0 mm and is 1.0 m long. The drop in pressure over the length of the tube is 200 kPa. What is the average speed of the oil

Answer 1

The average speed of the oil is 1 m/s.

Step-by-step explanation:

Given that,

Viscosity
`\eta= 0.25 N-s/m^2`

Radius r = 3.0 mm

Length = 1.0 m

Pressure = 200 kPa

We need to calculate the average speed of the oil

Using formula of pressure

`\Delta P=(8\pi\eta\rho v)/(A)`

`v=(A*\Delta P)/(8\pi\eta\rho)`

Where, A = area

`\rho` = density of oil

`\eta` = viscosity

Put the value into the formula

`v=(\pi*(3.0*10^(-3))^2*200*10^(3))/(8\pi*0.25*0.9)`

`v=1\ m/s`

Hence, The average speed of the oil is 1 m/s.