Chapter 3.9, Problem 3.24CT

(a)

Interpretation Introduction

Interpretation:

An explanation has to be given for the following observation,

In 2009, U.S Energy secretary Steven Chu suggested that painting roofs white would be one way to combat global warming.

Concept introduction:

Electromagnetic spectrum is a range of all types of electromagnetic radiation.

Radiant energy emitted by all matter whose temperature is greater than absolute zero

($0^o\text{}K$).

Radiant energy with short wavelength (higher frequency) will have the most energy and as the wavelength get longer, the energy decreases.

Global warming is a serious environmental issue, in which there is an increase in the overall temperature of the earth by various factors.

White colour reflects all wavelengths of light while black colour absorbs all wavelengths of light, absorbing energy will turn to heat energy

(b)

Interpretation Introduction

Interpretation:

An explanation has to be given for the following observation,

The idea of “ green roofs” is also attracting attention. Planting gardens in roof tops has benefits in addition to those of white roofs. But such gardens also have limitations.

Concept introduction:

Electromagnetic spectrum is a range of all types of electromagnetic radiation.

Radiant energy emitted by all matter whose temperature is greater than absolute zero

($0^o\text{}K$).

Radiant energy with short wavelength (higher frequency) will have the most energy and as the wavelength get longer, the energy decreases.

Light is an energy and heat is another form of energy.

White colour reflects all wavelengths of light while black colour absorbs all wavelengths of light, absorbing energy will turn to heat energy.