- #1

Justanotherstudent

a) object heated to 230 celius is placed inside a 25 celius room. Determine net rate of heat

loss due to raiation if object has surface area of 68 cm^2 and an emissivity of

0.780.

b) estimate the temp of object after 1 min if its density is 3.60 *10^3 kg/m^3 and its

specific heat is 768 J/kg*degress celius.

My work for a)

Actually I used a simliar equation to solve the first problem

change in Q/time = q for limitations of kboard

emissivity=e

bolstman constant= o

temp = T, Te= temp of environment To=temp of obj

a=area

q=eoA(Te^4-To^4)

so my quation for a was

q=.78(5.67*10^-8)(.68)(25^4-230^4)

q= -84.1 w/s

as for part b I have no idea how to work density into any of the equations I have at all.... driving me mad