Question 1

Suppose you throw a party to recognize that your physics class is over for the semester. You are out at a local pub with your friends and you make the comment "Look at that quarter sitting at the bottom of the aquarium. I now can tell you that its apparent weight is zero because it is underwater and supported by a buoyant force equal to the weight of the water it displaces". If your instructor were along and correctly commented on the scientific accuracy of your comment, what would they say?

Accepted Answer

The answer of Suppose you throw a party to recognize...

Question 2

Gravity creates
A) Constant motion in fluids
B) Lack of pressure on the top of all fluids
C) Uniform pressure in fluids
D) Pressure gradients in fluids

Accepted Answer

Gravity affects fluids by creating pressure gradients, where pressure increases with depth due to the weight of the fluid above. This is why, for example, pressure is higher at the bottom of a swimming pool than at the top.

Question 3

The pressure gradient set up in water standing is a glass is an example of ________ ________ in pressure, while variations in pressure due to water flowing faster in the smaller parts of a pipe are a type of ________ ________ in pressure.
A) static variation; buoyant force
B) static variation; dynamic variation
C) dynamic variation; constant value
D) dynamic variation; dynamic constancy

Accepted Answer

The pressure gradient in standing water represents a static variation in pressure because it is not moving, while changes in pressure in flowing water due to variations in pipe diameter are examples of dynamic variation in pressure, as these changes occur due to the motion of the fluid.

Question 4

Suppose you had a very long straw that could reach from a cup of water on the ground level to the top of a very tall building. When you suck on the straw in order to bring water up,
A) You could drink the water at any height with no problem
B) You could bring the water up to only a certain height in the straw because the atmosphere pushes down on the surface of the water by a given amount.
C) You could bring the water up to only a certain height in the straw because after it will flash freeze in the cup.
D) Water is too thick to be pulled up in the straw by more than a few inches.

Accepted Answer

The maximum height to which water can be sucked up in a straw is limited by atmospheric pressure. This pressure can only support a column of water up to about 10.3 meters (or 34 feet) at sea level. Beyond this height, the pressure is insufficient to counteract gravity, preventing water from being drawn any higher.

Question 5

Cities have to use water towers to supply water to because
A) The water tower has a vault of air that is pressurized.
B) Water moves fastest at the bottom of the water tower and this speed is transmitted uniformly throughout all water pipes below.
C) Water pressure at the top of the tower is transmitted through the water pipes.
D) Water pressure at the bottom of the tower is much higher than at the top.

Accepted Answer

The answer of Cities have to use water towers to...

Question 6

If the water pressure at a pump station at sea level 4,000,000 Pa, how high can the water be pumped uphill, and how fast will it flow out of a faucet at a washing station at sea level?
A) 408m; 90 m/s
B) 102m; 45 m/s
C) 102m; 90 m/s
D) 408 m; 45 m/s

Accepted Answer

The pressure at the pump station is 4,000,000 Pa, which is equal to the weight of a column of water 408 m high. The water will flow out of the faucet at a speed of 90 m/s, which is the speed of sound in water.

Question 7

Pressure potential energy
A) Can be stored for long periods of time to be transported and used.
B) Has to do with describing moving water and is only an abstract concept.
C) Has units of pressure.
D) Exists only in stationary fluids.

Accepted Answer

The answer of Pressure potential energy
A) Can be stored for...

Quiz 5: Fluids

Gravity creates

The pressure gradient set up in water standing is a glass is an example of in pressure, while variations in pressure due to water flowing faster in the smaller parts of a pipe are a type of in pressure.

Suppose you had a very long straw that could reach from a cup of water on the ground level to the top of a very tall building. When you suck on the straw in order to bring water up,

Cities have to use water towers to supply water to because

If the water pressure at a pump station at sea level 4,000,000 Pa, how high can the water be pumped uphill, and how fast will it flow out of a faucet at a washing station at sea level?

Pressure potential energy