11. pressure = ____.
- force/area
- output force/input force
- force × area
- volume × force
12. ____ is credited as the discoverer of air pressure.
- aristotle
- blaise pascal
- evangelista torricelli
- sir isaac newton
13. a sample of gas occupies 4.0 l at a pressure of 400 kpa. the temperature remains the same, but the pressure is decreased to 100 kpa. what is the new volume?
- 1.0 l
- 8.0 l
- 4.0 l
- 16.0 l
14. a hydraulic automobile jack has a small piston with an area of 2 cm² connected to a large piston with an area of 40 cm². a force of 400 n is applied to the small cylinder. what is the output force?
- 800 n
- 8,000 n
- 16,000 n
- 32,000 n
15. which of the following statements is not true?
- the atmospheric pressure at sea level is less than the atmospheric pressure on a mountaintop.
- the mercury barometer is more accurate than the aneroid barometer.
- fluids tend to move from areas of high pressure to areas of lower pressure.
- rising barometric pressure indicates good weather, while falling barometric pressure indicates poor weather
16. a hydrometer measures the ____ of liquids.
- cohesion
- pressure
- volume
- specific gravity
17. which of the following statements is not true?
- an object in a fluid will float if it is lighter than an equal volume of the fluid.
- a steel ship floats because it is hollow.
- a submarine varies its weight by using devices called swim bladders.
- a submarine reaches neutral buoyancy when the weight of the submarine equals the weight of the water displaced.
18. the air near the surface of the earth is ____ the air higher in the atmosphere.
- more dense than
- less dense than
- the same density as
- sometimes more dense, but sometimes less dense than
19. generally, the most important factor affecting drag is the ____.
- object’s shape
- object’s size
- object’s speed
- fluid’s density
20. which of the following statements regarding lift is not true?
- one of the most important factors that affects lift is the shape of the foil
- lift is a force on an object that is parallel to the direction of fluid flow.
- maximum lift is achieved at the critical angle of attack.
- longer, narrower foils produce more lift than shorter, wider foils.

Question

11. pressure = ____.
    - force/area
    - output force/input force
    - force × area
    - volume × force
12. ____ is credited as the discoverer of air pressure.
    - aristotle
    - blaise pascal
    - evangelista torricelli
    - sir isaac newton
13. a sample of gas occupies 4.0 l at a pressure of 400 kpa. the temperature remains the same, but the pressure is decreased to 100 kpa. what is the new volume?
    - 1.0 l
    - 8.0 l
    - 4.0 l
    - 16.0 l
14. a hydraulic automobile jack has a small piston with an area of 2 cm² connected to a large piston with an area of 40 cm². a force of 400 n is applied to the small cylinder. what is the output force?
    - 800 n
    - 8,000 n
    - 16,000 n
    - 32,000 n
15. which of the following statements is not true?
    - the atmospheric pressure at sea level is less than the atmospheric pressure on a mountaintop.
    - the mercury barometer is more accurate than the aneroid barometer.
    - fluids tend to move from areas of high pressure to areas of lower pressure.
    - rising barometric pressure indicates good weather, while falling barometric pressure indicates poor weather
16. a hydrometer measures the ____ of liquids.
    - cohesion
    - pressure
    - volume
    - specific gravity
17. which of the following statements is not true?
    - an object in a fluid will float if it is lighter than an equal volume of the fluid.
    - a steel ship floats because it is hollow.
    - a submarine varies its weight by using devices called swim bladders.
    - a submarine reaches neutral buoyancy when the weight of the submarine equals the weight of the water displaced.
18. the air near the surface of the earth is ____ the air higher in the atmosphere.
    - more dense than
    - less dense than
    - the same density as
    - sometimes more dense, but sometimes less dense than
19. generally, the most important factor affecting drag is the ____.
    - object’s shape
    - object’s size
    - object’s speed
    - fluid’s density
20. which of the following statements regarding lift is not true?
    - one of the most important factors that affects lift is the shape of the foil
    - lift is a force on an object that is parallel to the direction of fluid flow.
    - maximum lift is achieved at the critical angle of attack.
    - longer, narrower foils produce more lift than shorter, wider foils.

Accepted Answer

### Question 11
# Brief Explanations:
Pressure is defined as the force applied per unit area. So the formula is $ \text{Pressure} = \frac{\text{force}}{\text{area}} $. The other options (force × area, output force/input force, volume × force) do not match the definition of pressure.
# Answer:
A. force/area

### Question 12
# Brief Explanations:
Evangelista Torricelli is credited with the discovery related to air pressure (he invented the barometer which measures air pressure). Aristotle was a philosopher, Blaise Pascal worked on pressure in fluids, and Isaac Newton on motion/gravity.
# Answer:
C. Evangelista Torricelli

### Question 13
# Explanation:
## Step1: Identify the law (Boyle's Law)
Boyle's Law states $ P_1V_1 = P_2V_2 $ (temperature constant).
## Step2: Plug in values
$ P_1 = 400 \, \text{kPa}, V_1 = 4.0 \, \text{L}, P_2 = 100 \, \text{kPa} $. Solve for $ V_2 $: $ V_2=\frac{P_1V_1}{P_2}=\frac{400\times4.0}{100} $
## Step3: Calculate
$ \frac{1600}{100}=16.0 \, \text{L} $
# Answer:
D. 16.0 L

### Question 14
# Explanation:
## Step1: Hydraulic principle (Pascal's Law)
Pressure is transmitted equally: $ \frac{F_1}{A_1}=\frac{F_2}{A_2} $, so $ F_2 = F_1\times\frac{A_2}{A_1} $
## Step2: Plug in values
$ F_1 = 400 \, \text{N}, A_1 = 2 \, \text{cm}^2, A_2 = 40 \, \text{cm}^2 $
## Step3: Calculate
$ F_2 = 400\times\frac{40}{2}=400\times20 = 8000 \, \text{N} $
# Answer:
B. 8,000 N

### Question 15
# Brief Explanations:
Atmospheric pressure at sea level is **higher** than on a mountaintop (air is more dense at lower altitudes). The other statements: mercury barometers are more accurate than aneroid, fluids move from high to low pressure, and barometric pressure relates to weather (rising = good, falling = poor) are true.
# Answer:
A. The atmospheric pressure at sea level is less than the atmospheric pressure on a mountaintop.

### Question 16
# Brief Explanations:
A hydrometer measures the specific gravity (relative density) of liquids. Cohesion is attraction between similar molecules, pressure is force/area, volume is space occupied—none are measured by a hydrometer.
# Answer:
D. specific gravity

### Question 17
# Brief Explanations:
Submarines use ballast tanks (not swim bladders, which are in fish) to vary weight. The other statements: floating if lighter than equal volume fluid, steel ships float because hollow (displaces more water), and neutral buoyancy when weight equals displaced water are true.
# Answer:
C. A submarine varies its weight by using devices called swim bladders.

### Question 18
# Brief Explanations:
Air near Earth’s surface is more dense than higher up (gravity compresses it, so more mass per unit volume).
# Answer:
A. more dense than

### Question 19
# Brief Explanations:
The most important factor affecting drag is the object’s speed (drag is proportional to speed squared for fluid flow). Shape, size, and fluid density also affect drag, but speed is the most critical in general cases.
# Answer:
C. object’s speed

### Question 20
# Brief Explanations:
Lift is a force **perpendicular** (not parallel) to fluid flow. The other statements: foil shape affects lift, maximum lift at critical angle of attack, and longer/narrower foils produce more lift are true.
# Answer:
B. Lift is a force on an object that is parallel to the direction of fluid flow.

Sovi.AI - AI Math Tutor

QUESTION IMAGE

Question

Explanation:

Question 11

Step1: Identify the law (Boyle's Law)

Step2: Plug in values

Step3: Calculate

Answer:

Question 12