Heat transfer to the environment

Assignment Help Mechanical Engineering
Reference no: EM13880735

Spheres of 40-mm diameter heated to a uniform temperature of 400°C are suddenly removed from the oven and placed in a forced-air bath operating at 25°C with a convection coefficient of 300 W 1m:!. . K on the sphere surfaces, the thermo physical properties of the sphere material are p = 3000 kg/m3, c = 850 J/kg · K, and k = 15 W/m · K.

(a) How long must the spheres remain in the air bath for 80% of the thermal energy to be removed?

(b) The spheres are then placed in a packing carton that prevents further heat transfer to the environment. What uniform temperature will the spheres eventually reach?

Reference no: EM13880735

Questions Cloud

Develop a plan for how to resolve ethical and legal issues : Develop a plan for how to resolve ethical and legal issues
Analysis of starbucks corporation : Review the requirements of the Chapter 3 Mini-Case, parts b through h. Then apply those requirements to do an analysis of STARBUCKS CORPORATION (TICKER: SBUX). Don't complete the mini case itself, just STARBUCKS. Do the analysis on the basis of the f..
Surface temperature of the balls : If quenching is to occur until the surface temperature of the balls reaches 100°C, how long must the balls be kept in the oil? What is the center temperature at the conclusion of the cooling period?
What is the expected standard deviation of the stock : You are interested in buying a stock that has a price of $72. You have projected that next year there is: a 10% probability the stock will equal $1, a 20% probability the stock will equal $44, a 30% probability the stock will equal $83, a 30% probabi..
Heat transfer to the environment : The spheres are then placed in a packing carton that prevents further heat transfer to the environment. What uniform temperature will the spheres eventually reach?
Calculate the present value of these cash flows : Suppose that a firm's recent earnings per share and dividend per share are $3.15 and $2.60, respectively. Both are expected to grow at 6 percent. However, the firm's current P/E ration of 27 seems high for this growth rate. The P/E ratio is expected ..
Plasma spray deposition process : Consider conditions for which molten material at its fusion temperature Tf is deposited on a large substrate that is at an initial uniform temperature Ti.
Undertakes no new investment opportunities : BioTech expects to earn $2 million per year in perpetuity if it undertakes no new investment opportunities. There are 100,000 shares outstanding. The firm will have an opportunity at Year 1 to spend $2 million on a new project. The new project will i..
What price seems to be most profitable : Create a spreadsheet similar to the example to model price setting by the dominant firm. (If you completed Problem S1 of Chapter 7, you need only make slight modifications in that spreadsheet.)

Reviews

Write a Review

Mechanical Engineering Questions & Answers

  Package design

Package Design Brief: Assume you are the packaging engineer for a large consumer products company. In this company, the Packaging Design Briefs are initiated by the marketing group and forwarded to the Package Engineering group.

  Mechanical engineering questions

Define dynamic viscosity, Determine the centroid, Pressure due to the height of liquid, Advantage of changing the liquid, Calculate the total moment about the hinge of the seal gate.

  Automatic control

DOF system and Find the differential equation describing the system

  Write a paper on boyle''s law

Write a paper on Boyle's law and describe Compression and Combustion stroke . Also explain Charles's law and illustrate SI engine and CI engine.

  Verify the law for parallelogram of forces

To Verify the law for parallelogram of forces, law for triangle of forces and law of polygon of forces. These laws are very useful to calculate unknown forces in very short time.

  Discharge pressure of the compressor

What is the discharge revised discharge pressure of the compressor.

  The Case for Global Accounting Standards

The role of IFRS in both developing and developed capital markets.

  Wind turbine

Wind turbines are becoming more and more common as a method of energy production, wind turbines by their very nature are dynamic and are subject to and create their own internal and external kinematics and kinetics.

  Advanced design methodologies

8 x product engineering and design review (week 2 – 12), ~3 pages per item which must contain a brief description of the product then delve into concepts such as materials selection, manufacturing methods, life cycle analysis, recyclability and overa..

  Design of absorption column and the cooler

Design of absorption column and the cooler. Process design of other units should be completed along with pipe sizes.

  Determine the maximum total bending moment

Determine maximum total bending moment (static plus dynamic) of the beam under steady-state conditions.

  Force of the water on the gate

Determine the magnitude of the horizontal and vertical components of the force of the water on the gate.

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd