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.

there are no correct statementd on the list of choices you provided.

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.