Question

800 W/m3 of heat is generated within a 10 cm diameter nickel- steel sphere for which...

800 W/m3 of heat is generated within a 10 cm diameter nickel- steel sphere for which k = 10 W/m·K. The environment is at 20◦C and there is a natural convection heat transfer coefficient of 10 W/m2K around the outside of the sphere. What is its center temperature at the steady state? [21.37◦C.]

Science   Physics   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

'please rate if it help|

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
In a steel spherical reactor with a heat transmission coefficient (10 + X) W / mK,...
In a steel spherical reactor with a heat transmission coefficient (10 + X) W / mK, water is boiled at 350 oC. The inner diameter of the tank is 80 cm and the wall thickness is (5+ (X / 2)) cm. This tank is insulated with (X) cm thick concrete (k = 2.5 W / mK). Outdoor heat transfer coefficient (10+ (X)) W / m2K, indoor heat transfer coefficient is 500 W / m2K. Calculate both surface temperatures of the...
A spherical object (50 cm diameter, c=0.46 kJ/kg*C, k = 42 W/m*C, density = 7800 kg/m3...
A spherical object (50 cm diameter, c=0.46 kJ/kg*C, k = 42 W/m*C, density = 7800 kg/m3 ) is initially at a uniform temperature of 450 C. It is suddenly placed in a constant temperature environment of 100 C. The convection transfer coefficient is 500 W/m2*C. How long would it take for temperature in the center of the sphere to cool down to 150 C? Note: Bi for a sphere is (hD)/(6k).Suggestion: First calculate Biot number, then determine if T is...
A long 10 cm × 20 cm rectangular cross section steel bar ݇ k= 63.9 W/mK...
A long 10 cm × 20 cm rectangular cross section steel bar ݇ k= 63.9 W/mK and alpha=18.8*10^-6 m^2 /s was heated to an initial temperature of 450°C. The steel bar is allowed to cool in a room with a temperature of 25°C and convection heat transfer coefficient of 25 W/m^2 K. The bottom surface of the bar is insulated while the other surfaces are exposed to convection. With a uniform nodal spacing of 5 cm, determine the duration required...
A heated spherical ceramic object (diameter = 10 cm) is held in a large enclosure whose...
A heated spherical ceramic object (diameter = 10 cm) is held in a large enclosure whose walls are maintained at a temperature of 300K. The sphere has an emissivity of 0.7. The rest of the enclosure is filled with stagnant nitrogen at a temperature of 300 K. Properties of the sphere: Density = 4500 kg/m3; heat capacity = 400 J/(kg.K); thermal conductivity = 22 W/(m.K). Assume properties of the sphere do not vary with temperature. a. Determine the rate of...
A 2 cm thick steel pipe (thermal conductivity = 43 W/[m.C]) with 6 cm inside diameter...
A 2 cm thick steel pipe (thermal conductivity = 43 W/[m.C]) with 6 cm inside diameter is being used to convey steam from a boiler to process equipment for a distance of 40 m. The inside pipe surface temperature is 115 degrees C, and the outside pipe surface temperature is 90 degrees C. Calculate the total heat loss to the surroundings under steady-state conditions.
A 1 m outer diameter spherical tank made of AISI 304 steel with 10 cm wall...
A 1 m outer diameter spherical tank made of AISI 304 steel with 10 cm wall thickness contains solid iced water at 0°C. Air at 25°C flows outside the tank with a velocity of 1 m/s. Determine the rate of heat transfer to the tank and the mass rate ( m_dot) at which ice melts. Ignore convection effects of the melting ice. The latent heat of fusion of water at 0°C is 333.7 kJ/kg. Thanks!
a) A 12 mm diameter mild steel sphere (k = 42.5 W/m K) is exposed to...
a) A 12 mm diameter mild steel sphere (k = 42.5 W/m K) is exposed to cooling airflow at 27 0C resulting in the convective coefficient, h = 114 W/ m2 K. The relevant properties of mild steel are given as follows: Density , /7850 2 mkg  Specific heat K kgJc p / 475 and thermal diffusivity hr m /043.0 2  Determine: (i) Time required to cool the sphere (lumped parameter system) from 540 0C to 950C. [7...
After heat treatment, the 2-cm thick metal plates (k = 180 W/m·K, ρ = 2800 kg/m3,...
After heat treatment, the 2-cm thick metal plates (k = 180 W/m·K, ρ = 2800 kg/m3, and cp = 880 J/kg·K) are conveyed through a cooling chamber with a length of 10 m. The plates enter the cooling chamber at an initial temperature of 500°C. The cooling chamber maintains a temperature of 10°C, and the convection heat transfer coefficient is given as a function of the air velocity blowing over the plates h = 33V0.8, where h is in W/m2·K...
A stainless-steel fin (k = 16 W/m. °C) has a length of 15 cm and a...
A stainless-steel fin (k = 16 W/m. °C) has a length of 15 cm and a square cross section 12.5 by 12.5 mm attached to a wall maintained at 250 °C. The heat-transfer coefficient is 40 W/m. °C, and the environment temperature is 90 °C. Calculate the percentage increase in heat transfer after attaching the fin.
A 3-m-internal-diameter spherical tank made of 1-cm-thick stainless steel is used to store iced water at...
A 3-m-internal-diameter spherical tank made of 1-cm-thick stainless steel is used to store iced water at 0°C. The tank is located outdoors at 18°C. Assume the entire steel tank to be at 0°C and thus the thermal resistance of the tank to be negligible. The heat of fusion of water at atmospheric pressure is hif = 333.7 kJ/kg. The emissivity of the outer surface of the tank is 0.75, and the convection heat transfer coefficient on the outer surface can...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT