Iplace a 500-g ice cube (initially at 0°c) in a styrofoam box with wall thickness 1.0 cm and total surface area 600 cm2 .

if the air surrounding the box is at 20°c and after 4 hours the ice is completely melted, what is the conductivity of the styrofoam material? (lf = 80 cal/g)
a. 9.6 × 10−5cal/s⋅cm⋅°c
b. 2.8 × 10−6cal/s⋅cm⋅°c
c. 1.15 × 10−2cal/s⋅cm⋅°c
d. 2.3 × 10−4cal/s⋅cm⋅°c

Para resolver este problema es necesario aplicar los conceptos relacionados a la conductividad térmica, para lo cual se tiene matematicamente que

Where,

K = thermal conductivity

A = Cross-sectional Area

= Change at temperature

x = Distance

= Difference of time

= Heat exchange energy

Our values are given as follow,

The total heat required to change the phase of ice would be

Where Lf Latent heat of fussion and m is the mass.

Replacing we would have:

Therefore the correct answer is D.

where's the following? you gotta add it to know what the choices are

explanation:

resonant frequency