This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Suppose that the Department of Energy develops a new reversible engine that has a coefficient of ... (Read 55 times)

ericka1

  • Hero Member
  • *****
  • Posts: 544
on: Jul 29, 2018
Suppose that the Department of Energy develops a new reversible engine that has a coefficient of performance (COP) of 4.0
 
  when operated as a refrigerator and a COP of 5.0 when operated as a heat pump. What is its thermal efficiency when operated as a heat engine doing work?
  A) 20 B) 10 C) 45 D) 80 E) 25

Question 2

For a certain metal, light of frequency 7.24  10-14 Hz is just barely able to dislodge photoelectrons from the metal. (h = 6.626  10-34 J  s, 1 eV = 1.60  10-19 J, e = 1.60  10-19 C)
 
  (a) What will be the stopping potential if light of frequency 8.75  10-14 Hz is shone on the metal?
  (b) What is the work function (in electron-volts) of this metal?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

jlaineee

  • Sr. Member
  • ****
  • Posts: 380
Reply #1 on: Jul 29, 2018
Answer to Question 1

A

Answer to Question 2

(a) 0.625 V (b) 3.00 eV


ericka1

  • Hero Member
  • *****
  • Posts: 544
Reply #2 on: Jul 29, 2018
Thanks


jlaineee

  • Sr. Member
  • ****
  • Posts: 380
Reply #3 on: Jul 29, 2018
Welcome :)


« previous next »
 

Did you know?

The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."

Did you know?

The familiar sounds of your heart are made by the heart's valves as they open and close.

Did you know?

Vampire bats have a natural anticoagulant in their saliva that permits continuous bleeding after they painlessly open a wound with their incisors. This capillary blood does not cause any significant blood loss to their victims.

Did you know?

Medication errors are more common among seriously ill patients than with those with minor conditions.

Did you know?

According to the American College of Allergy, Asthma & Immunology, more than 50 million Americans have some kind of food allergy. Food allergies affect between 4 and 6% of children, and 4% of adults, according to the CDC. The most common food allergies include shellfish, peanuts, walnuts, fish, eggs, milk, and soy.

Rotary engine operates on the four-stroke cycle but uses a rotor instead of a piston and crankshaft ... Rotary engine operates on the four-stroke cycle but uses a rotor instead of a piston and crankshaft ...
Overview of a computer-controlled high-pressure common rail V-8 diesel engine. Overview of a computer-controlled high-pressure common rail V-8 diesel engine.
Effect of a catalyst on activation energy Effect of a catalyst on activation energy
The energy budget The energy budget
Energy drinks Energy drinks
Consider the production function ( ) 0.5 0.5 Y = AK L . Suppose both saving rate (s) and the ... Consider the production function ( ) 0.5 0.5 Y = AK L . Suppose both saving rate (s) and the ...
Video: Introduction to Eating Disorders

For a complete list of videos, visit our video library