# Physics

A class of 11 students taking an exam has a power output per student of 122 W. Assume that the initial temperature of the room is 18.8oC and that its dimensions are 6.40 m by 14.5 m by 3.50 m. What is the temperature (in oC, do not enter units) of the room at the end of 54.0 min if all the heat remains in the air in the room and none is added by an outside source? The specific heat of air is 840 J/kg*oC, and its density is about 1.25E-3 g/cm3

** I keep getting different answers ranging from 30-40 and nothing is correct! HelP!

1. 0
2. 0
1. power*timeinseconds=specifheatair*densityair*volumeair(Tf-Ti)

Tf=Ti+power*time/(specheatair*density*volume)

Tf=18.8+54*60*122/(840*6.4*14.5*3.5*density)
now change denstity to kg/m^3
density=1.25E-3g/cm^3*(100cm/m)^3*1kg/1000g= 1.25E-3*E6*E-3=1.25kg/m^3

Tf= about one C higher. Check my calcs

posted by bobpursley

## Similar Questions

1. ### physics

A class of 11 students taking an exam has a power output per student of 122 W. Assume that the initial temperature of the room is 18.8oC and that its dimensions are 6.40 m by 14.5 m by 3.50 m. What is the temperature of the room
2. ### Physics

60) A class of 10 students taking an exam has a power output per student of about 200W. 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
3. ### math

a student’s grade in a class is simply the mean of five 100-point exams a. If the student has grades of 77, 73, 97, and 89 on the first four exams, what is the students’ grade before taking the last exam? b. What is the lowest
4. ### Physics

A class of 11 students taking an exam has a power output per student of 124 W. Assume that the initial temperature of the room is 18.7°C and that its dimensions are 6.00 m by 14.5 m by 3.40 m. What is the temperature (in °C, do
5. ### statistics and probability

It is known that an exam scores of students in STAT 2507 follow a normal distribution with a mean of 70% and a standard deviation of 9%. (A) If a student must obtain a mark of 50% to pass the exam, what proportion of students fail
6. ### economics

A professor of economics gives multiple choice exams each semester. He curves the exams by giving the maximum possible points to the high score on the exam. For example, if a 50 question exam is worth 100 points and the top score
7. ### Math

First period: 85, 83, 74, 70, 88,95,89,72,90,83,77,91,98,89,82,84 Second period: 95,89,82,81,72,69,100,97,75,91,82,79,96,81,80,95,89,97,83,71 Mark is a student in the first period class. His score on the exam was 95%. Zoe is a
8. ### English

There are 7 classes for first year students. Each class is composed of about 30 students. Emily is a student of Class 1-2. One of his classmates who went to the same elementary school asks: Which class are you in? What is the
9. ### English

Please help with this question that has been bothering me! I take bio college class and we have graduate/student assistant for labs & when taking an exam. The professor is never there during those sections.Due to my low exam
10. ### JAVA PROGRAMMING

im new to java and this is my first assignment can anyone help me solving it: compile the class final grades, based on the students’ scores obtained in the classwork, mid-term, and final exams. According to the course syllabus,

More Similar Questions