Chapter 5.4, Problem 5.8YT

(a)

Interpretation Introduction

Interpretation:

A slice of pizza contains 217 kcal (217 Cal). This value of energy has to be expressed in kilojoules.

Concept Introduction:

Calorie is the unit of energy and is the energy required to raise temperature of $1g{H}_{2}Oby{1}^{o}C$ .

Unit conversion

$\begin{array}{c}\text{1}\text{cal}=\text{4}\text{.184}\text{J}\\ \text{1}\text{kcal}=\text{1000}\text{cal}=\text{1}\text{Cal}\\ \text{1}\text{kcal}=\text{4}\text{.184}\text{kJ}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The number of 1-kg books that could lift to a shelf  2m off the floor has to be calcultaed with the amount of energy from metabolizing one slice of pizza.

Concept Introduction:

Calorie is the unit of energy and is the energy required to raise temperature of $1g{H}_{2}Oby{1}^{o}C$ .

Unit conversion

$\begin{array}{c}\text{1}\text{cal}=\text{4}\text{.184}\text{J}\\ \text{1}\text{kcal}=\text{1000}\text{cal}=\text{1}\text{Cal}\\ \text{1}\text{kcal}=\text{4}\text{.184}\text{kJ}\end{array}$