Test 2

Atmospheric pressure is about 100000 Pa. At what depth in water does this pressure double?

10 meters (m)

Assume you have an adjustable volume container that starts out with a pressure of 100,000 Pa, a volume of 1 m^3, and temperature of 300 K. If the temperature and number of particles in the container stays the same, what is the new pressure in the container if the volume is reduced to 0.5 m^3?

200,000 Pa

The onset of turbulent flow happens for a Reynolds number of about

2000

You are a deep sea diver and are carrying out pressure tests on your air tanks, which is required by inspection rules. A gas cylinder is filled with a gas at a temperature of 300 K and pressure 200000 Pa. The temperature of the gas is then raised to 400 K. Assuming the volume and number of particles stay the same what is the new pressure?

266667

Convert 100 ºC to Kelvin:

373.15 K

Water weighs about 10 N per liter. A 4.0 liter ball is pushed underwater. What is the buoyant force on the ball?

40 Newtons (N)

If you wanted to take a steel bar with an initial length of 1.5 m and expand it to 1.51 m just by increasing the temperature what change in temperature would be necessary to accomplish this task? (Steel α = 12×10-6 1/K)

555.6 K

Density is defined as the volume per unit mass.

False

Entropy is a measurement of order in a system.

False

Gauge pressure and absolute pressure refer to the exact same value.

False

In pipe flow, flow rate and velocity are not related.

False

Laminar fluid flow is noisier than turbulent fluid flow.

False

Pressure exerts a force parallel to the area over which the force is applied.

False

The Carnot cycle only uses irreversible processes during the entire cycle.

False

The onset of turbulence inside a pipe and around an object in a fluid happens around the same Reynolds number.

False

Thermodynamics is the study of motion and its relationship to position, velocity, and acceleration.

False

Water is the only material that has a triple point in its phase diagram.

False

When a typical solid is heated it shrinks in size.

False

Which of the following is the SI unit for temperature?

Kelvin

Who invented the internal combustion engine?

Otto

Gravity creates

Pressure gradients in fluids

"The entropy of an isolated system never decreases." Which Law of Thermodynamics is this?

Second

Suppose that we are able to send astronauts to Mars and they engage in a game of golf on the red planet's surface. Given that the atmosphere on Mars is considerably less dense than our own, how will the path of the ball be affected?

There is less drag and gravity, so the ball will go further than if there were air

A dense fluid (assume mercury) will sink when poured in a less dense fluid (assume water).

True

A nozzle increases the velocity of pipe fluid flow while dropping the pressure of the fluid.

True

According to Poiseuille's law a small change in pipe diameter can cause a large change in flow rate.

True

Assume an object is suspended in fluid. The bottom of the object feels a larger pressure than the top of the object.

True

Assume you have a 100 gram block of ice and a 100 gram glass of liquid water sitting in front of you. In terms of order and disorder the block of ice has more order than the glass of liquid water.

True

Heat transfer is only possible between two objects if the two objects have different temperatures.

True

In an enclosed container when water reaches the boiling temperature at standard atmospheric pressure the water vapor and liquid water near the surface are in equilibrium.

True

In the attached PV diagram figure, the shaded area in between ABCD is the net work out of this theoretical Carnot Cycle.

True

Liquids and gasses are both considered fluids

True

One of the basic requirements of a thermometer is that it must give repeatable results within experimental error.

True

The amount of water vapor that air can hold changes with temperature.

True

The lake "turnover" that occurs during the winter season in lakes/ponds is due to temperature-density variation in water.

True

Turbulent flow is characterized by noisy chaotic mixing fluid flow.

True

Cities have to use water towers to supply water because

Water pressure at the bottom of the tower is much higher than at the top

Why are failures in dams more likely to occur closer to the bottom of the dam?

Water pressure is higher at the bottom

"Two objects in thermal equilibrium with a third object are in thermal equilibrium with each other." Which Law of Thermodynamics is this?

Zeroth

The air in this room consists of countless tiny, independent molecules. You can be sure that all the oxygen molecules will not all shift spontaneously to the other side of the room (leaving you without oxygen) because that would

be extremely unlikely and therefore violate the 2nd law of thermodynamics

The first law of thermodynamics is a re - statement of the law of

conservation of energy

Aerodynamic forces consist of

drag and lift

As the Reynolds number increases,

flow is going from being viscous dominated to inertia dominated and therefore turbulent.

It is a hot summer day and your friend's apartment has no air conditioning. However, a brand new refrigerator lies unopened in the center of the living room. Being a creative person, your friend closes all the doors and windows of the apartment, unpacks the refrigerator, plugs it in, and turns it on. Your friend then opens the refrigerator door and uses a small fan to circulate the air past the refrigerator and throughout the room. After the refrigerator has operated for a few minutes, the average temperature in the room is

higher than it was before

Flowing honey is less likely to become turbulent than flowing water because

honey's large viscosity favors laminar flow

You stop for a cappuccino at a coffee shop and notice that the tiny white bubbles of steamed milk remain on the surface of the coffee. These air-filled bubbles stay where they are, rather than descending into the coffee or rising into the air, because they are

less dense than the coffee but more dense than the air above the coffee

A squirt gun is a simple type of water pump in which a plunger attached to the trigger forces water out of a nozzle and across the room. When you squeeze the trigger of the gun, water squirts out of the nozzle because

the pressure inside the gun is higher than atmospheric pressure

The reason fast-moving water makes noise is

turbulence

When you pour honey into a bowl, it flows smoothly. If you did the same with water, it would splash. These different behaviors occur because honey's high

viscosity keeps it flowing smoothly while water's low viscosity allows inertia to break its flow into many separate pieces

You open the refrigerator in your room and put in a case of room-temperature root beer. After an hour, the root beer is ice cold. If your room air did not exchange any heat with the outdoor air during that time, the room air will be

warmer because the refrigerator will have pumped heat out of the root beer and into the room air.