Q: A vertical column is filled with water ($$\rho = 1000 \ \mathrm{kg/m^3$}) $$and open to the atmosphere at the top. If the column is $$2.0 \ \mathrm{m}$$ tall, what is the pressure at the base of the column in pascals?

$$p = 1.21 \times 10^5$ \ \mathrm{Pa}$$

Q: A barometer uses mercury ($$\rho = 13,600 \ \mathrm{kg/m^3$}) to $$measure atmospheric pressure. If the height of the mercury column is $$0.76 \ \mathrm{m}$$, what is the atmospheric pressure in pascals?

$$p = 1.01 \times 10^5$ \ \mathrm{Pa}$$

Q: A manometer contains oil ($$\rho = 900 \ \mathrm{kg/m^3$}) $$and measures the pressure of a gas. If the oil column height difference is $$0.20 \ \mathrm{m}$$, what is the gauge pressure of the gas in pascals?

$$p_g = 1.8 \times 10^3$ \ \mathrm{Pa}$$

Question 1

A hydraulic lift in a car repair shop uses oil with a density of $$900 \ \mathrm{kg/m^3$}. If $$the area of the small piston is $$0.0030 \ \mathrm{m^2$}$$ and the area of the large piston is $$0.0491 \ \mathrm{m^2$}$$, how much force must be applied to the small piston to lift a $$1300 \ \mathrm{kg}$$ car (ignore the height difference)?

Accepted Answer

$$F_1 = 381$$ \ \mathrm{N}$$

Question 2

A vertical column is filled with water ($$\rho = 1000 \ \mathrm{kg/m^3$}) $$and open to the atmosphere at the top. If the column is $$2.0 \ \mathrm{m}$$ tall, what is the pressure at the base of the column in pascals?

Accepted Answer

$$p = 1.21 	imes 10^5$ \ \mathrm{Pa}$$

Question 3

Which of the following statements about fluids is correct?

Accepted Answer

A gas is compressible and a liquid is incompressible.

Question 4

A barometer uses mercury ($$\rho = 13,600 \ \mathrm{kg/m^3$}) to $$measure atmospheric pressure. If the height of the mercury column is $$0.76 \ \mathrm{m}$$, what is the atmospheric pressure in pascals?

Accepted Answer

$$p = 1.01 	imes 10^5$ \ \mathrm{Pa}$$

Question 5

A manometer contains oil ($$\rho = 900 \ \mathrm{kg/m^3$}) $$and measures the pressure of a gas. If the oil column height difference is $$0.20 \ \mathrm{m}$$, what is the gauge pressure of the gas in pascals?

Accepted Answer

$$p_g = 1.8 	imes 10^3$ \ \mathrm{Pa}$$

Question 6

Which of the following best describes the difference between absolute pressure and gauge pressure?

Accepted Answer

Gauge pressure is the pressure above atmospheric pressure.

Question 7

A submarine is at a depth of $$300 \ \mathrm{m} in $$seawater ($$ho = 1030 \ \mathrm{kg/m^3$}). $$What is the total pressure at this depth in atmospheres? ($$1 \ \mathrm{atm} = 1.01 	imes 10^5$ \ \mathrm{Pa})$$

Accepted Answer

$$p = 31 \ \mathrm{atm}$$

Question 8

If the density of a fluid doubles while the depth remains constant, what happens to the pressure at that depth (ignoring atmospheric pressure)?

Accepted Answer

The pressure doubles.

Question 9

A closed tube contains water and is open to the atmosphere at one end. If the height of the water column is $$1.5 \ \mathrm{m}$$, what is the pressure at the bottom of the tube in terms of atmospheric pressure $$p_0$$?

Accepted Answer

$$p = p_0$ + \rho g h$$

Question 10

Which of the following is NOT a correct SI unit conversion?

Accepted Answer

$$1 \ \mathrm{psi} = 14.7 \ \mathrm{Pa}$$

Question 11

A hydraulic lift is used to raise a car by applying a force of $$500 \ \mathrm{N} to a $$small piston with area $$0.01 \ \mathrm{m^2$}. If $$the large piston has an area of $$0.1 \ \mathrm{m^2$}$$, what is the maximum weight of the car that can be lifted (neglecting fluid height differences)?

Accepted Answer

$$5000 \ \mathrm{N}$$

Question 12

Which of the following best explains why pressure in a connected fluid at rest is the same at all points on a horizontal line?

Accepted Answer

Because pressure increases with depth, and depth is constant along a horizontal line.

Question 13

A tire gauge reads a pressure of $$220 \ \mathrm{kPa}. $$What is the absolute pressure inside the tire if atmospheric pressure is $$101 \ \mathrm{kPa}$$?

Accepted Answer

$$321 \ \mathrm{kPa}$$

Question 14

Which of the following is a correct statement about the forces exerted by a fluid on a submerged object?

Accepted Answer

The force is always perpendicular (normal) to the surface.

Question 15

A vertical U-tube is filled with two different fluids, oil ($$\rho = 900 \ \mathrm{kg/m^3$}) $$and water ($$\rho = 1000 \ \mathrm{kg/m^3$}). If $$the oil column is $$0.30 \ \mathrm{m}$$ high, what is the equivalent height of the water column that balances the oil column?

Accepted Answer

$$h_{water} = 0.27 \ \mathrm{m}$$

Chapter 14: Fluids and Elasticity – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards