Complete and Clear Question:
A person puts a few apples into the freezer at -15°C to cool them quickly for guests who are about to arrive. Initially, the apples are at a uniform temperature of 20°C, and the heat transfer coefficient on the surfaces is 8 W/m2·K. Treating the apples as 9-cm-diameter spheres and taking their properties to be
840 kg/m3,
3.81 kJ/kg·K, k = 0.418 W/m·K, and
, determine the center and surface temperatures of the apples in 1 h. Also, determine the amount of heat transfer from each apple. Solve this problem using analytical one-term approximation method (not the Heisler charts).
Answer:
Temperature at the center of the apple, T(t) = 11.215°C
Temperature at the surface of the apple, T(r,t) = 2.68°C
Amount of heat transfer from each apple, Q = 21.47 kJ
Explanation:
For clarity and easiness of expression, the calculations are handwritten and attached as a file. Check the attached files for the complete calculation.
This is the half life of the substance. The half life is the time it takes for the substance to become reduced by half as a consequence of decay.
Answer:
If we use a mixture of red and blue light, the blue toy car might reflect deep magenta color. If the toy car is made up of metal, it might reflect glittery magenta color. If the intensity of the blue color is greater, the toy car might show dark blue color
Explanation:
is this right please let me know:D
When a dielectric material is inserted between two plates of capacitor that are connected to a battery, you would observe that both the charge and the capacitance of the capacitor would change. This is due to the dielectric material which is able to transmit electric force.