Physics Principle and Problems

Paul W. Zitzewitz, Todd George Elliott, David G. Haase

Chapter 13

States of Matter - all with Video Answers

Educators

Section 1

Properties of Fluids

Problem 1

The atmospheric pressure at sea level is about $1.0 \times 10^{5} \mathrm{Pa}$. What is the force at sea level that air exerts on the top of a desk that is $152 \mathrm{cm}$ long and $76 \mathrm{cm}$ wide?

Sean Dougherty

Sean Dougherty

Numerade Educator

Problem 2

A car tire makes contact with the ground on a rectangular area of $12 \mathrm{cm}$ by $18 \mathrm{cm} .$ If the car's mass is $925 \mathrm{kg},$ what pressure does the car exert on the ground as it rests on all four tires?

Sean Dougherty

Numerade Educator

Problem 3

A lead brick, $5.0 \mathrm{cm} \times 10.0 \mathrm{cm} \times 20.0 \mathrm{cm},$ rests on the ground on its smallest face. Lead has a density of $11.8 \mathrm{g} / \mathrm{cm}^{3} .$ What pressure does the brick exert on the ground?

Sean Dougherty

Numerade Educator

Problem 4

In a tornado, the pressure can be 15 percent below normal atmospheric pressure. Suppose that a tornado occurred outside a door that is $195 \mathrm{cm}$ high and $91 \mathrm{cm}$ wide. What net force would be exerted on the door by a sudden 15 percent drop in normal atmospheric pressure? In what direction would the force be exerted?

Sean Dougherty

Numerade Educator

Problem 5

In industrial buildings, large pieces of equipment must be placed on wide steel plates that spread the weight of the equipment over larger areas. If an engineer plans to install a 454 -kg device on a floor that is rated to withstand additional pressure of $5.0 \times 10^{4} \mathrm{Pa}$, how large should the steel support plate be?

Sean Dougherty

Numerade Educator

Problem 6

A tank of helium gas used to inflate toy balloons is at a pressure of $15.5 \times 10^{6} \mathrm{Pa}$ and a temperature of $293 \mathrm{K}$. The tank's volume is $0.020 \mathrm{m}^{3} .$ How large a balloon would it fill at 1.00 atmosphere and $323 \mathrm{KP}$

Sean Dougherty

Numerade Educator

Problem 7

What is the mass of the helium gas in the previous problem? The molar mass of helium gas is $4.00 \mathrm{g} / \mathrm{mol}$

Sean Dougherty

Numerade Educator

Problem 8

A tank containing $200.0 \mathrm{L}$ of hydrogen gas at $0.0^{\circ} \mathrm{C}$ is kept at $156 \mathrm{kPa}$. The temperature is raised to $95^{\circ} \mathrm{C},$ and the volume is decreased to $175 \mathrm{L}$. What is the new pressure of the gas?

Sean Dougherty

Numerade Educator

Problem 9

The average molar mass of the components of air (mainly diatomic oxygen gas and diatomic nitrogen gas) is about $29 \mathrm{g} / \mathrm{mol}$. What is the volume of $1.0 \mathrm{kg}$ of air at atmospheric pressure and $20.0^{\circ} \mathrm{C} ?$

Sean Dougherty

Numerade Educator

Problem 10

Pressure and Force Suppose that you have two boxes. One is $20 \mathrm{cm} \times 20 \mathrm{cm} \times 20 \mathrm{cm} .$ The other
is $20 \mathrm{cm} \times 20 \mathrm{cm} \times 40 \mathrm{cm}$
a. How does the pressure of the air on the outside of the two boxes compare?
b. How does the magnitude of the total force of the air on the two boxes compare?

Sean Dougherty

Numerade Educator

Problem 11

Meteorology A weather balloon used by meteorologists is made of a flexible bag that allows the gas inside to freely expand. If a weather balloon containing $25.0 \mathrm{m}^{3}$ of helium gas is released from sea level, what is the volume of gas when the balloon reaches a height of $2100 \mathrm{m},$ where the pressure is $0.82 \times 10^{5}$ Pa? Assume that the temperature is unchanged.

Sean Dougherty

Numerade Educator

Problem 12

Gas Compression In a certain internal-combustion engine, $0.0021 \mathrm{m}^{3}$ of air at atmospheric pressure and $303 \mathrm{K}$ is rapidly compressed to a pressure of $20.1 \times 10^{5} \mathrm{Pa}$ and a volume of $0.0003 \mathrm{m}^{3} .$ What is the final temperature of the compressed gas?

Supratim Pal

Numerade Educator

Problem 13

Density and Temperature Starting at $0^{\circ} \mathrm{C}$, how will the density of water change if it is heated to $4^{\circ} \mathrm{C} ?$ To $8^{\circ} \mathrm{C} ?$

Sean Dougherty

Numerade Educator

Problem 14

The Standard Molar Volume What is the volume of 1 mol of a gas at atmospheric pressure and a temperature of $273 \mathrm{K?}$

Sean Dougherty

Numerade Educator

Problem 15

The Air in a Refrigerator How many moles of air are in a refrigerator with a volume of $0.635 \mathrm{m}^{3}$ at a temperature of $2.00^{\circ} \mathrm{C}$ ? If the average molar mass of air is $29 \mathrm{g} / \mathrm{mol},$ what is the mass of the air in the refrigerator?

Sean Dougherty

Numerade Educator

Problem 16

Critical Thinking Compared to the particles that make up carbon dioxide gas, the particles that make up helium gas are very small. What can you conclude about the number of particles in a $2.0-L$ sample of carbon dioxide gas compared to the number of particles in a 2.0 - $L$ sample of helium gas if both samples are at the same temperature and pressure?

Sean Dougherty

Numerade Educator