Unit 8 Test

Question 1

Tricia’s giant jack-in-the-box, Jerry, has now come to life, and wants revenge on her. While Tricia is away, Jerry devises a hydraulic press under Tricia’s bed. The press allows Jerry to apply 20 times the force on Tricia’s bed that he applies to the piston on his side. What is the ratio of the area of the piston on Jerry’s side to the area of the piston under the bed?

Answer 1

1/20

Question 2

Paul has a mass M and a volume Vp. He goes snorkeling and completely submerges himself in the water. Assuming that he is not exerting any force personally, what is the net force on Paul?

Answer 2

(pw)(Vp)g-mg

Question 3

When viewed from above, a particular car has an area A1. Each of its four tires holds a pressure PT, and contacts the ground with an area of A2. If atmospheric pressure is Patm, which of the following is the correct expression for the weight of the car?

Answer 3

4PTA2

Question 4

Which of the following statements is true for any completely enclosed ideal fluid?

Answer 4

Any change in pressure is transmitted equally to all points in the fluid.

Question 5

True or false?
In a house with a water supply that is contained in a water tower, the pressure on the second floor is greater than the pressure on the first floor.

Answer 5

false

Question 6

True or false?
When an ideal fluid is placed under pressure, the fluid at the bottom of the container becomes more compressed and denser.

Answer 6

false

Question 7

Evaluated the following as true or false. If a container with columns of different diameter is filled with water, the water level in the column with the greatest surface area will be lower.

Answer 7

false

Question 8

If the radius of a pipe carrying water is doubled for a stretch of the pipe, the velocity of the water___________.

Answer 8

is quartered

Question 9

If the radius of a pipe carrying water is doubled for a stretch of the pipe, the volume flow rate of the water____________.

Answer 9

remains the same

Question 10

Bernoulli’s equation does not include the effects of______________.

Answer 10

friction

Question 11

The derivation of Bernoulli’s equation relies on _______________.

Answer 11

conservation of energy

Question 12

A dolphin trailing one of the Navy’s aircraft carriers decides to swim underneath the carrier. Does the presence of the ship affect the pressure changes the dolphin feels as it dives?

Answer 12

No, the pressure remains the same as when the ship wasn’t there.

Question 13

A lift force is exerted on an airplane wing as a result of _______________.

Answer 13

Bernoulli’s principle

Question 14

The main pipe coming into a factory is 8 m in diameter, and the water in that pipe enters the building at 1 m / s. Once inside, however, the pipe divides into four pipes that are each 4 m in diameter. Which of the following is the velocity of the water in the smaller pipes?

Answer 14

The velocity in the smaller pipes is the same as the velocity in the larger pipe.

Question 15

True or false?
When a sudden gust of wind blows past an open window that has a curtain hanging straight down inside of a room, the curtain blows into the room.

Answer 15

false

Question 16

Which of the following statments about fluids is not correct?

Answer 16

The density of an incompressible fluid depends upon the pressure to which the fluid is subjected.

Question 17

Which of the following statements concerning density is not correct?

Answer 17

Density is a property of the type of solid or fluid and is affected by the size of the sample.

Question 18

True or false?
Although neither gases nor liquids have a definite shape, liquids have a definite volume, while gases expand to fill any volume. Thus, liquids are fluids, and gases are not fluids.

Answer 18

false

Question 19

Consider a person’s eardrum at a depth of 3 meters below the surface of water. Which of the following is the force exerted on the eardrum by the water pressure? Assume that the person’s eardrum is 0.36 cm2 in area.

Answer 19

1.06 N

Question 20

Consider the diagram of the apparatus where the liquid in the A side is water, and the liquid in the B side is mercury. The two liquids are at the same height and are separated by the partition as shown. The density of mercury is 13.6 g / cm3. When the partition is removed, the boundary between the liquids will ______________.

Answer 20

move to the left

Question 21

A constant force is applied to the smaller side of a hydraulic jack. If the cross-sectional area of the larger piston of a hydraulic jack is increased, the load it can lift _______________.

Answer 21

increases

Question 22

A piece of metal is placed in a series of liquids. The liquids have sequentially greater density. The buoyant force of the liquid on a cubic foot of the submerged metal ____________.

Answer 22

increases

Question 23

Water flows at a rate of 0.250 L / s (liters per second) through a hose with an internal diameter of 20.00 cm. The nozzle of the hose is a circular opening of diameter 10.00 cm. If 1 ml of water is equivalent to 1 cm3, what is the speed of the water when it emerges?

Answer 23

3.18 cm / s

Question 24

Bernoulli’s equation ____________.

Answer 24

is derived from conservation of energy

Question 25

Consider a smooth sphere of radius r falling through air with a speed v. Assume that the flow in this case is laminar. Which of the following is correct?

Answer 25

For a sphere of radius r, the force of viscous drag is proportional to the velocity and is opposite to the direction of the velocity vector