![mmaglaya1](/avatars/19762.jpg)
mmaglaya1
14.07.2019 •
Social Studies
What famous experiments did ivan pavlov john b watson and mary cover jones conduct?
Solved
Show answers
More tips
- S Style and Beauty Choosing a Hair Straightener: Specific Criteria to Consider...
- F Family and Home How to Remove Tar Stains: Tips and Recommendations from Experts...
- F Family and Home How to Remove Fading from Clothes: Tips and Tricks...
- S Sport How to Do a Jumping Split...
- H Health and Medicine How Did Inna Lose Weight on Dom 2?...
- F Family and Home How to Properly Fold Napkins in a Napkin Holder?...
- F Food and Cooking How to Set Up Ventrilo - The Ultimate Guide...
- S Science and Technology How to Make a Homemade Smoker: The Ultimate Guide...
- A Auto and Moto Battle for the Relocation of The Cherkizovsky Market: Who Won?...
- C Computers and Internet How Do You Refill Cartridges?...
Answers on questions: Social Studies
- S Social Studies A. Anong aspekto ng kultura ang nakikita sa opisyal na simbolo(pang ekonomiya panlipunan at paniniwala ...
- B Biology In response to seasonal changes in temperature, many organisms must alter the composition of their plasma membranes to maintain the proper degree of fluidity. as...
- B Biology The skin excretes (blank) which is made up of water, salts, and chemicals like urea. The (blank) excrete carbon dioxide and water. The large intestine produces (blank)...
- M Mathematics 1) find the volume of a cylinder with diameter 22 in and height 15 in. a. 22,796.4 in3 b. 5,699.1 in3 c. 1,796.08 in2 d. 330 in3 2 ) how do you find the volume of...
Ответ:
Question:
A piston–cylinder device contains 0.85 kg of refrigerant- 134a at -10°C. The piston that is free to move has a mass of 12 kg and a diameter of 25 cm. The local atmospheric pressure is 88 kPa. Now, heat is transferred to refrigerant-134a until the temperature is 15°C. Determine (a) the final pressure, (b) the change in the volume of the cylinder, and (c) the change in the enthalpy of the refrigerant-134a.
a) 90.4 kPa
b) 0.0205 m³
c) 17.4 kJ/kg
Explanation:
Given:
Mass, m = 0.85 kg
a) The final pressure here is equal to the initial pressure. Let's use the formula:
= 90398 Pa
≈ 90.4 KPa
Final pressure = 90.4 kPa
b) Change in volume of the cylinder:
To find the initial and final volume, let's use the values from the A-13 table for refrigerant-134a, at initial values of 90.4 kPa and -10°C and final values of 90.4 kPa and 15°C
v1 = 0.2302m³/kg
h1 = 247.76 kJ/kg
v2 = 0.2544 m³/kg
h2 = 268.2 kJ/kg
Change in volume is calculated as:
Δv = m(v2 - v1)
Δv = 0.85(0.2544 - 0.2302)
= 0.0205 m³
Change in volume = 0.0205 m³
c) Change in enthalpy
Let's use the formula:
Δh = m(h2 - h1)
= 0.85(268.2 - 247.76)
= 17.4 kJ/kg
Change in enthalpy = 17.4 kJ/kg