Chapter 10, Problem 47A

(a)

Interpretation Introduction

Interpretation: The energy 462.4 kJ needs to be converted to kilocalories.

Concept introduction: Kilo joule is an energy unit derived from SI, which is equivalent to 1000 Joules. Joule is quantity of energy that converted to an object when one Newton force acts as on an object over a area of one meter in direction of motion.

Answer to Problem 47A

462.4kJ=11052kcal

Explanation of Solution

1kJ=1000J

1cal=4.184J

1kcal=1000cal

Conversion of 462.4kJ to kcal is as follows:

  $\begin{array}{c}\text{462}\text{.4}\cancel{\text{kJ}}\text{×}\frac{\text{1000}\cancel{\text{J}}}{\text{1}\cancel{\text{kJ}}}\text{×}\frac{\text{1}\cancel{\text{cal}}}{\text{4}\text{.184}\cancel{\text{J}}}\text{×}\frac{\text{1kcal}}{\text{1000}\cancel{\text{cal}}}=\frac{\text{462}\text{.4}\times \text{1000Kcal}}{\text{4}\text{.184}\times 1000}\\ =110.52\text{kcal}\end{array}$

Thus 462.4kJ=11052kcal

(b)

Interpretation Introduction

Interpretation: The energy 18.28 kJ needs to be converted into kilocalories.

Concept introduction: Kilo joule is an energy unit derived from SI, which is equivalent to 1000 Joules. Joule is quantity of energy that converted to an object when one Newton force acts as on an object over a area of one meter in direction of motion.

Answer to Problem 47A

18.28kJ=4.37kcal

Explanation of Solution

1kJ=1000J

1cal=4.184J

1kcal=1000cal

Conversion of 18.28kJ to kcal is as follows:

  $\begin{array}{c}\text{18}\text{.28}\cancel{\text{kJ}}\text{×}\frac{\text{1000}\cancel{\text{J}}}{\text{1}\cancel{\text{kJ}}}\text{×}\frac{\text{1}\cancel{\text{cal}}}{\text{4}\text{.184}\cancel{\text{J}}}\text{×}\frac{\text{1kcal}}{\text{1000}\cancel{\text{cal}}}=\frac{\text{18}\text{.28}\times \text{1000Kcal}}{\text{4}\text{.184}\times 1000}\\ =4.37\text{kcal}\end{array}$

Thus 18.28kJ=4.37kcal

(c)

Interpretation Introduction

Interpretation: The energy 1.014 kJ needs to be converted to kilocalories.

Concept introduction: Kilo joule is an energy unit derived from SI, which is equivalent to 1000 Joules. Joule is quantity of energy that converted to an object when one Newton force acts as on an object over a area of one meter in direction of motion.

Answer to Problem 47A

1.014kJ=0.242kcal

Explanation of Solution

1kJ=1000J

1cal=4.184J

1kcal=1000cal

Conversion of 1.014kJ to kcal is as follows:

  $\begin{array}{c}\text{1}\text{.014}\cancel{\text{kJ}}\text{×}\frac{\text{1000}\cancel{\text{J}}}{\text{1}\cancel{\text{kJ}}}\text{×}\frac{\text{1}\cancel{\text{cal}}}{\text{4}\text{.184}\cancel{\text{J}}}\text{×}\frac{\text{1kcal}}{\text{1000}\cancel{\text{cal}}}=\frac{\text{1}\text{.014}\times \text{1000Kcal}}{\text{4}\text{.184}\times 1000}\\ =0.242\text{kcal}\end{array}$

Thus 1.014kJ=0.242kcal

(d)

Interpretation Introduction

Interpretation: The energy 190.5 kJ needs to be converted to kilocalories.

Concept introduction: Kilo joule is an energy unit derived from SI, which is equivalent to 1000 Joules. Joule is quantity of energy that converted to an object when one Newton force acts as on an object over a area of one meter in direction of motion.

Answer to Problem 47A

190.5kJ=45.53kcal

Explanation of Solution

1kJ=1000J

1cal=4.184J

1kcal=1000cal

Conversion of 190.5kJ to kcal is as follows:

  $\begin{array}{c}\text{190}\text{.5}\cancel{\text{kJ}}\text{×}\frac{\text{1000}\cancel{\text{J}}}{\text{1}\cancel{\text{kJ}}}\text{×}\frac{\text{1}\cancel{\text{cal}}}{\text{4}\text{.184}\cancel{\text{J}}}\text{×}\frac{\text{1kcal}}{\text{1000}\cancel{\text{cal}}}=\frac{\text{190}\text{.5}\times \text{1000Kcal}}{\text{4}\text{.184}\times 1000}\\ =45.53\text{kcal}\end{array}$

Thus 190.5kJ=45.53kcal