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...
The water in a thin steel container with a diameter of 12 cm boils. Between the...
The water in a thin steel container with a diameter of 12 cm boils. Between the bottom of the container and boiling water; heat transfer coefficient 10 k W / m 2 K Passing into the water; heat flux 40 k W / m 2 a) Find the surface temperature of the bottom of the container. b) Find the heat given to the water and the amount of evaporated water for 30 minutes.
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.
To harden a steel sphere having a diameter of 50.8 mm, it is heated to 1033...
To harden a steel sphere having a diameter of 50.8 mm, it is heated to 1033 K and then dunked into a large water bath at 300 K. Determine the time for the center of the sphere to reach 366.5 K, and the temperature at 10 mm from the centre. The surface coefficient can be assumed as 710 W/m^2.K and k=45 W/m.K and alpha=0.0325 m2/h.
A 1-shell-2-tube pass heat exchanger is made of a steel alloy (thermal conductivity 45.4 W/(m K)....
A 1-shell-2-tube pass heat exchanger is made of a steel alloy (thermal conductivity 45.4 W/(m K). It is used to cool distilled water from 34oC to 29oC using water which flows inside tubes with an outer diameter of 19 mm and an inner diameter of 16 mm. The number of tubes in the shell is 160 (80 per pass). The mass flow rate of distilled water in the shell is 76180 kg/h. The cold water enters the heat exchanger at...
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.
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT