Given :
Energy in one slice of bread , e = 50 kcal .
A 1- lb loaf of bread contains 18 slices .
1 cal = 4.18 J .
To Find :
How many Joules of energy are obtained by eating 1.00 g of bread .
Solution :
We know , 1 lb = 0.45 kg = 450 g .
So , mass of 1 slice bread in gram is :
[tex]m=\dfrac{450}{18}\\\\m=25 \ g[/tex]
So , 25 g bread contains 50 kcal of energy .
Energy in 1 g of bread is :
[tex]c=\dfrac{50}{25}\\\\c=2\ kcal[/tex]
Therefore , energy in joules is [tex]2\times 4.18\ J=8.36\ J[/tex] .
Hence , this is the required solution .
