%Brandon Smith
%Homework due: 2-7-07
%Program will determine amount of heat needed to convert different stages
%of water as temp. rises

g=input('enter the number of grams ')
t1=input('enter the initial temperature ')
t2=input('enter the final temperature ')

if (t1<0)
    if (t2<0)
        heat = g*(t2-t1)*.48
    elseif (t2<100) 
        heat = g*(0-t1)*.48 + g*79.8 + g*(t2)
    else
         heat = g*(0-t1)*.48 + g*79.8 + g*(100)+ g*540 + g*.475*(t2-100)
    end
end