Fluid dynamics questions | form five Physics

1. What is the terminal velocity?
2. Derive an expression for terminal velocity of a spherical body falling from rest through a viscous fluid.

State Newton`s law of viscosity and hence deduce the dimensions of the coefficient of viscosity.

In an experiment to determine the coefficient of viscosity of motor oil, the following measurements are made;

• Mass of galss sphere =1.2x10^-4kg
• Diameter of sphere = 4.0x10^-3m
• Terminal velocity of sphere=5.4x10^-1ms^-1
• Density of oil =860kgm^-1

Calculate the coefficient of viscosity of the oil.

Briefly explain the carburetor of a car as applied to Bernoulli`s theorem.

Three capillaries of the same length but with internal radii 3R, 4R and 5R are connected in series and a liquid flows through them under streamline conditions. If the pressure across the third capillary is 8.1mm of liquid. Find the pressure across the first capillary.

Give reasons for the following observations as applied in fluid dynamics.

1. A flag flutter when strong winds are blowing on a certain day.
2. A parachute is used while jumping from an airplane
3. Hotter liquids flow faster than cold ones.

1. Write down the Bernoulli`s equation for fluid flow in a pipe and indicate the term which will disappear when the fluid is stopped.
2. Name the principle on which the continuity equation is based.
3. Basing on the applications of Bernoulli`s principle, briefly explain why two ships which are moving parallel and close to each other experience an attractive force.

A sphere is dropped under gravity through a fluid of viscosity, . Taking average acceleration as half of initial acceleration , show that the time taken to attain terminal velocity if independent of fluid density.

Water is flowing through a horizontal pipe having different cross-sections at two points A and B. The diameters of the pipe at A and B are 0.6m and 0.2m respectively. The pressure difference between point A and B is 1m column of water. Calculate the volume of water flowing per second.

The flow rate of water from a tap of diameter 1.25cm is 3 litres per minute. The coefficient of viscosity of water is 10^-1Nsm^-2. Determine the Reynolds number and then state the type of flow of water.