   Chapter 11, Problem 62AP

Chapter
Section
Textbook Problem

A class of 10 students taking an exam has a power output per student of about 200 W. Assume the initial temperature of the room is 20°C and that its dimensions are 6.0 m by 15.0 m by 3.0 m. What is the temperature of the room at the end of 1.0 h if all the energy remains in the air in the room and none is added by an outside source? The specific heat of air is 837 J/kg · °C, and its density is about 1.3 × 10−3 g/cm3.

To determine
Temperature of the room at the end of 1.0 h.

Explanation

Section1:

To determine: The energy added to air in one hour.

Explanation:

Given Info: Power output per student is about 200 W, time is 1.0 h.

200 W of power is added by each student, So total power is the sum of

10 students.

Formula to calculate total power is,

Ptot=10Peach

• Ptot is total power output.
• Peach is power output by each student,

Formula to calculate the power output is,

Q=Ptott

• Q is heat added to the room,
• Ptot is total power output,
• t is the time,

Use 10Peach for Ptot to rewrite the above equation.

Q=10Peacht

Substitute 200 W for Peach , 1.0 h for t  to find Q.

Q=10(200W)(1.0h)(3600s1.0h)=7.20×106J

Thus, the energy added to the air in one hour is 7.20×106J

Section 2:

To determine: To determine the mass of air in the room.

Answer: mass of the air is 351kg

Explanation:

Given Info: Length of the room is 6.0 m, breadth of the room is 15.0 m and height of the room is 3.0 m.

Formula to calculate the volume of the room is,

Vroom=lbh

• Vroom is volume of the room,
• l is the length of the room,
• b is the breadth of the room,
• h is the height of the room,

Formula to calculate the mass of the air is,

m=ρVroom

• m is the mass air in the room,
• ρ is the density of the air,

Use lbh in the above equation to rewrite m.

m=ρlbh

Substitute 1.3kg/m3 for ρ , 6.0 m for l, 15.0 m for b, 3.0 m for h to find m.

m=(1.3kg/m3)(6

Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

The fiber-rich portion of the wheat kernel is the bran layer. T F

Nutrition: Concepts and Controversies - Standalone book (MindTap Course List)

4-17 Balance each equation.

Introduction to General, Organic and Biochemistry

What is genomics?

Human Heredity: Principles and Issues (MindTap Course List) 