A metal cube of 0.1 m sides is being cooled down uniformly from 300°C to 30°C by placing it in cold water at 10°C. The convection coefficient of water around the cube is 40 W/m².K. The properties of the cube material are as follows - thermal conductivity: 137 W/m-K, density: 1600 kg/m³; specific heat: 800 J/kg.K. Neglect radiation. Find the time required for cool 1426-28 cooling.
Q: 7-46. The beam is subjected to a shear of V = 800 N. Determine the average shear stress developed in…
A:
Q: A slender, rigid bar of mass m and length I is pinned to a massless collar as shown in the figure…
A: Solution: Given Data: To Find: Acceleration of the collar.
Q: Why does intercooling reduce work in a comprssor (such as in the Brayton cycle), but it doesn't…
A: The Brayton cycle and the Rankine cycle vary in that the former uses a liquid as one of its…
Q: A hollow shaft with an outside diameter of 3.1 in. and an inside diameter of 2.8 in. is subjected to…
A:
Q: 4) High humidity air is used conditioning of dough before baking. An air stream at 40 °C and 30%…
A: Given data, Initial air temperature, Ti = 40 °C Initial relative humidity of air, ∅i=30% Final…
Q: 9.28 Determine the maximum allowable uniform heat flux that may be imposed at a wall heating panel 1…
A:
Q: If k = 23 kip/in and W = 329 kip, determine the period of vibration in seconds.
A: Given:Spring constant, k=23 kip/inMass, m=329 kip
Q: The boom in the figure below (Figure 1) weighs 3000 NN and is attached to a frictionless pivot at…
A:
Q: From the given truss, find the force of member AH, Load 1 = 178 kN, Load 2 = 399 kN Solve this using…
A:
Q: truss is subjected to the loading shown. Determine the support reaction forces and the forces in…
A:
Q: Problem 10.34 Take that a = 36 mm. (Figure 1) Figure Part A Iy = 5a Determine the moment of inertia…
A:
Q: A -2 2 Semi-circle 0 Determine the moment of inertia and radius of gyration about the x- axis for…
A:
Q: You are given 1) the normal to the slip plane and the normal to the slip direction angle with the…
A:
Q: 1. A circular disk has a density p(r) which varies as a function of distance from the center of the…
A: (a) To find: The total mass of the disK. Given: The density of the disk is ρ(r)=ρo1-rR. Calculation:…
Q: A cylindrical rod of stainless steel is insulated on its exterior surface except for the ends. The…
A:
Q: le) Name four methods used for strengthening of metals. What is the common principle that these…
A:
Q: A slingshot is propelled with initial veloc- ity of 40 m/s at an angle of 60° to the top of a…
A:
Q: A three-point bending test is performed on a glass specimen having a rectangular cross section of…
A:
Q: 15mg per kg body weight 25mg per 1cc 5.5lbs give: ____ cc
A:
Q: Ax Find Ax and Hy. 25+ - B с D A 204+ N 204+ M. 204L 2011 ↓ 50 lbs 50lbs ↓ 50165 E 204 K ↓ 50lbs F G…
A: Given: All the forces acting on the truss are vertically downwards. And there is no horizontal…
Q: 18. The part in Fig. 2-44 is made of 1045 steel, quenched and drawn, σult = 820 MPa, Typ = 620 MPa.…
A: Given: Mmin= 1040000 N.mm Mmax= 5000000 N.mm D=150 mm t= 25mm d = 75 mm
Q: If a = 9 in., locate the distance to the centroid of the member's cross-sectional area. (Figure 1)…
A: Draw the given diagram.
Q: 1.) dx dt + 7x = 5 cos 2t 2 ← Equation 1
A: Given equation is a 1st order differential equation with x as dependent variable and t as the…
Q: * quiny 500 M T₁. T.₁. Fig.2
A: Given system is Newton’s second law, Inertia force = net restoring force
Q: Required information The helium-filled balloon in the image is tethered at 20°C and 1 atm with a…
A: Given Temperature T= 20 0c String is negligible mass and drag diameter of the balloon d =58 cm =0.58…
Q: 7. A steel pulley with a mean rim radius of 120 mm is rotated at a speed of 1100 rpm. If the mass of…
A: To find: The centrifugal force. Given: The mass of the rim is m=5 kg. The radius of the rim is r=120…
Q: A built-up beam is constructed by welding two channels separated by a distance b = 1.25 in to two (5…
A:
Q: W M 84 X m
A: Given, To find the equation of motion using Langrange's approach we need to find the Kinetic…
Q: Learning outcome Fundamental.2 evaluation A B The car travels around a circular track having a…
A:
Q: ] Calculate the diffusivity in square meters per second for the diffusion of zinc in copper at…
A:
Q: 5a 3a. ਹਨ ਧਨ Ja
A: Given system, a= 36 mm using the moment of inertia of rectangle about centroidal axis I=…
Q: The flexural strength and associated volume fraction porosity for two specimens of the same ceramic…
A: Given data:- Flexural strength (σ1) =100 MPa for 0.05 porosity Flexural strength (σ2) =50 MPa for…
Q: How large must F2 be if both wheels are to have the same angular acceleration?
A:
Q: 31.6What load in N must be applied to a 25 mm round steel bar 2.5 m long (E = 207 Gpa) to stretch…
A:
Q: Fatigue test are carried out
A: Fatigue test or Rotating beam is carried to know the fatigue stress, in which the beam is rotating…
Q: fixed support at the base. The support at the top prevents both lateral deflec- tion and rotation.…
A:
Q: Calculate the pressure of the air in the sealed tank shown in Fig. 6.25 that would cause the…
A:
Q: 23.A machine has a selling price of P500,000 after given 15% discount. Find the original amount.
A:
Q: m ks): A vibrating system consists of a mass of 17.5 kg, a spring of stiffness C Q5 35.0 N/cm, and a…
A: As per our guidelines we are supposed to solve only 3 subparts if multiple subparts are asked.…
Q: Compute the moments of inertia with respect to the X-X and Y-Y centroidal axes for the following…
A:
Q: Figure Txy 1 of 1 σx LI
A: Given system,
Q: A student sits on a freely rotating stool holding two dumbbells, each of mass 2.97 kg (see figure…
A:
Q: An electron is at rest in an oscillating magnetic field along the z-direction with B₂-Bo cos(wt)…
A: Given, An electron is at rest in an oscilllating magnetic fieldis, B→= Bocos w+k^Where Bo…
Q: A space to be conditioned has a sensible heat load of 80 kw and a latent heat load of 20 kw and is…
A:
Q: Pendulum A is swinging with v= 0.3 m/s and reducing at a rate of 0.5 m/s every second when 0 = 30°…
A: Given v = 0.3 m/s a = 0.5 m/s²
Q: The 14.6-lb lever OA with 9.6-in. radius of gyration about O is initially at rest in the vertical…
A:
Q: Estimate (a) the maximum, and (b) the minimum thermal conductivity values (in W/m-K) for a cermet…
A: Introduction In this problem, we will compute the maximum and minimum thermal conductivities of a…
Q: The creep data for plastic polyacetal is shown, what is the strain for the material tested at…
A: Given data:- stress applied=40 N/mm2 Time =1000 s To find :- strain of the material
Q: Determine the range of weights W for which the 111-lb block is in equilibrium. All wheels and…
A:
Q: To what height will the jet of water rise for the conditions shown in Fig. 6.40?
A: Given data: p=12 psig
Step by step
Solved in 2 steps with 2 images
- Show that the rate of heat conduction per unit length through a long, hollow cylinder of inner radius ri and outer radius ro, made of a material whose thermal conductivity varies linearly with temperature, is given by qkL=TiTo(rori)/kmA where Ti = temperature at the inner surface To = temperature at the outer surface A=2(rori)/ln(ro/ri)km=ko[1+k(Ti+To)/2]L=lenthofcyclinderThe interior wall of a large, commercial walk-in type meat freezer is covered under normal operating conditions with a 2-cm thick layer of ice. One day, a power outage cuts electricity to the refrigeration system of the freezer. Estimate the time required to melt this layer of ice if it has a mass density of 700kg/m3 and a latent heat of fusion of 334 kJ/kg. Consider the air temperature inside the freezer to be 20C with a heat transfer coefficient of 2W/m2K for convection from the freezer surface to air, and clearly state the assumptions made in your calculations.As a designer working for a major electric appliance manufacturer, you are required to estimate the amount of fiberglass insulation packing (k = 0.035 W/m K) that is needed for a kitchen oven shown in the figure below. The fiberglass layer is to be sandwiched between a 2-mm-thick aluminum cladding plate on the outside and a 5-mm-thick stainless steel plate on the inside that forms the core of the oven. The insulation thickness is such that the outside cladding temperature does not exceed 40C when the temperature at the inside surface of the oven is 300C. Also, the air temperature in the kitchen varies from 15Cto33C, and the average heat transfer coefficient between the outer surface of the oven and air is estimated to be 12.0W/m2K. Determine the thickness of the fiberglass insulation that is required for these conditions. What would be the outer surface temperature when the inside surface of the oven is at 475C?
- A 0.6-cm diameter mild steel rod at 38C is suddenly immersed in a liquid at 93C with hc=110W/m2K. Determine the time required for the rod to warm to 88C.Shown below is an insulated copper block that receives energy at a rate of 100 W from anembedded resistor. If the block has a volume of 10-3 m3and an initial temperature of 20oC, howlong would it take, in minutes, for the temperature to reach 60oC? Copper has a specific heatcapacity ccu = 0:385 kJ/ kg.K and a density of cu = 8930 kg/m3.3.4 Estimate the rate of heat loss due to radiation from a covered pot of water at 95 ° C. How does this compare with the 60 W that is lost due only to convection and conduction losses? What amount of energy input would be needed to maintain the water at its boiling point for 30 minutes? The polished stainless steel pot is cylindrical, 20 cm in diameter and 14 cm high, with a tight-fitting flat cover. The air temperature in the kitchen is about 25 ° C. State any assumptions you make in deriving your estimates
- ⦁ Two water columns are at different ⦁ temperatures, one being at 35oC and the other being at 18oC. The water columns are separated by a glass wall of area 1m by 2m and a thickness of 0.005m. Calculate the amount of heat transfer. (Thermal Conductivity of glass is 1.6 W/mK)1. A beverage cooler is in the shape of a cube, 42 cm on each inside edge. Its 3.0-cm thick wall are made up of plastic (kr = 0.050 W/mK). When the outside temperature is 20°C, how much ice will melt each hour? Tice is 0°C. 2. One of the possible mechanisms of heat transfer in human body is conduction through body fat. Suppose that heat travels through 0.03 m of fat in reaching the skin, which has a total surface area of 1.7 m² and a temperature of 34°C. Find the amount of heat that reaches the skin in half an hour, if the temperature at the body, interior is maintained at the normal value 37°C ? Thermal conductivity of body fat is k = 0.2 J/sm°C. 3. The air in a room is at 25°C and outside temperature is 0°C. The window of the room has an area of 2m² and thickness 2mm. Calculate the rate of loss of heat by conduction through window ? Thermal conductivity for glass is 1 Wm¯'degree!.On a winters day the outside temperature of a 15 inch thick concrete wall is -25F, the wall is 16 ft long and 10 ft high. How manu BTU are required to keep the inside of the wall at 75F? Assume walls thermal conductivity is 0.8BTU/h ft F. Show detailed solutions
- Q2: A: The exterior wall of a single-story office building near Chicago is 3 m high and 15 m long. The wall consists of 100-mm face brick, 40-mm polystyrene insulating board. 150-mm lightweight concrete block, and an interior 16-mm gypsum. The wall contains three single-glass of 3 mm thickness windows 1.5 m high by 2 m long. Calculate the heat loss through the wall at design conditions if the inside temperature is (20 °C). The outside temperature is (-18 "C).A food product with 82% moisture content is being frozen. Estimate the specific heat of the product at -8°C when 82% of the water is in a frozen state. The specific heat of dry product solid is 2.5 kJ/(kg °C). Assume specific heat of water at -10°C is similar to specific heat of water at 0°C.2-1. Temperature Response in Cooling a Wire. A small copper wire with a diameter of 0.792 mm and initially at 366.5 K is suddenly immersed in a liquid held constant at 311 K. The convection coefficient h 85.2 W/m K. The physical properties can be assumed constant and are k =374 W/m K, c, = 0.389 kJ/kg K, and p = 8890 kg/m2. (a) Determine the time in seconds for the average temperature of the wire to drop to 338.8 K (one-half the initial temperature difference). (b) Do the same but for h 11.36 W/m2 K (c) For part (b), calculate the total amount of heat removed for a wire 1.0 m р u (A long. (a) t 5.66 s Ans. the Smou hire is lons asbume Nhere rraolius , here radlius yinder hitu x Chapter 14 Principles of Unsteady-State Heat Transfer