Quiz1Problem1Solution

Quiz1Problem1Solution - Physics-7A Lecture A Quiz 1 Problem...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Physics-7A Lecture A Quiz 1 Problem 1 Solution Part (a) 30% This is a closed system, so we have: E A + E B = Q + W = 0 E A = 1750 J – 250 J = +1500J E B = -1500J Then the intermediate point for B is (1000 J, 100ºC). Either writing that, or pointing to the correct spot on the B graph was counted as a correct answer. Part (b) 30% No, A will not reach its boiling point. There are two ways to express the correct answer, both equally valid. Answer 1: At the intermediate point, T A = 70ºC, T B = 100ºC. Heat will continue to go from B to A, so T B goes down while T A goes up. Then the final temperature is somewhere between 70ºC and 100ºC. But the boiling point of A is 100ºC, and therefore the system must end up below the boiling point of A. So A remains a liquid. Answer 2: For A to get to its boiling point, it will have to gain 250 J. And the system is closed, so B looses 250 J. But then from the graph, T B = 50ºC. So B will end up at a lower temperature than A! This
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern