An ordinary egg can be approximated as a 5.5- cm diameter sphere whose properties are roughly k = 0.6 W/m·k and α = 0.14 × 10-6 m2 /s. The egg is initially at a uniform temperature of 4°C and is dropped into boiling water at 97°C.

Taking the convection heat transfer coefficient to be h = 1400 W/m2 ·K, determine how long it will take for center of the egg to reach 70°C.

The time required to reach the center temperature of egg at 70 °c  is     0.3 sec.

Explanation:

Given data

Diameter (d) = 5.5 cm = 0.055 m

K = 0.6

h= 1400

Initial temperature = 4 °c= 277 K

Ambient temperature = 97 °c= 370 K

Center temperature T = 70°C = 343 K

Thermal diffusivity  α =   ×

We know that

× =

4.28 ×

We know that from the lumped parameter  analysis

Put all the values in above equation we get

0.29 = 0.965 × t

t = 0.3 sec

Therefore the time required to reach the center temperature of egg at 70 °c is 0.3 sec.

they are non-matter

explanation:

they are non-matter. basically, any type of energy or any abstract concept is an example of something that does not matter. other examples include dreams, magnetism, radio, and hate

potential energy is directly proportional to height.

more height = more potential energy.

greatest increase in height = greatest increase in potential energy

where are the points with the greatest increase in height ?

has to be c-e or d-e .