Physics Homework quiz #4

A smooth and orderly movement of a fluid is described as

• turbulent

• unlikely

• laminar

• laminated

In laminar flow the fluid flows in

• circles

• swirls

• layers

• a hurry

Which of the following is not involved in calculating the Reynolds number

• relative velocity

• cross sectional area of the object

• density of the fluid

• length of the object moving through the fluid

A Reynold's number of 10 would indicate a flow which is

• laminar

• turbulent

• chaotic

• extreme

A Reynold's number of about 1 million indicates that the flow will be

• laminar

• turbulent

• chaotic

• extremely turbulent

Why might the Reynold's number be important to an engineer working on exhaust systems?

• Combustion gases are fluids

• Combustion gases are fluids and turbulent flows would slow the rate of exhaust

• Combustion gases are fluids and laminar flow would slow the rate of exhaust

Changing the direction of your hand moving through a fluid can reduce the drag force because

• the cross sectional area is increased

• the cross sectional area is decreased

• the velocity is decreased

• the velocity is increased

Relative velocity of objects moving through a fluid is the most important factor because

• speed kills

• its value is squared

• we divide by velocity

• velocity is square rooted

When the relative velocity of an object moving through a fluid is 0 the drag force is

• 1000

• 100

• 10

• 0

For a certain object in a certain fluid the drag force equation can be abbreviated to the equation shown because

• b is a better value

• the only thing that really matters is the velocity

• the cross sectional area, drag coefficient, density remain constant and only need to be calculated once = b

• none of the other values are important