Chapter 22, Problem 20A

(a)

To determine

To Explain: The one-way valve of green-house effect.

Answer to Problem 20A

The green-house acts like one-way valve as it traps the heat coming from outside. Most of vegetation including flowers can grow inside it because of optimal temperature.

Explanation of Solution

Introduction:

A greenhouse is a transparent chamber which allows the sunlight. Most of the part of the sunlight gets trapped into the chamber to maintain good temperature for vegetation.

The sunlight enters in the greenhouse chamber and reflected back. Some part of the sunlight suffers continuous reflection from the surface of the greenhouse and gets trapped inside it. Earth’s surface is transparent for the short wavelength infrared radiations emitted by the sun and does not lets long wavelength infrared radiation to escape out. The plants and flowers inside the greenhouse will grow properly due to the optimal temperature that is adjusted by greenhouse effect.

Conclusion:

Hence, the green-house act like one-way valve as it traps the short wavelength infrared radiations and does not lets long wavelength infrared radiations to escape the earth’s surface.

(b)

To determine

To Explain: Whether the greenhouse effect is more pronounced for florist’s greenhouses or for Earth’s surface.

Answer to Problem 20A

A greenhouse traps the long wavelength infrared radiations emitted by the objects and thus increases the warmth and heat in and around that area.

Explanation of Solution

Introduction:

A greenhouse is a transparent chamber which allows sunlight. Most of the part of the sunlight gets trapped into the chamber to accommodate the good temperature for vegetation.

Some plants and vegetation cannot grow in cold winter climatic conditions. For which there is need of an optimum temperature for their growth and blooming. An artificial warmth is created at a few places to support the optimum temperature for a plant or flower to bloom and blossom by building a green house chamber which traps the heat of the sun and does not let it escape to the outside atmosphere which is cold. But since it is an artificial system, it traps the heat lesser than compared to the trapping of heat energy in our earth’s atmosphere. Our earth’s atmosphere being composed of many gases and human activities contributing to accumulate greenhouse gases in it, is capable of trapping much more heat energy than is trapped in a greenhouse prepared by florists.

Conclusion:

Hence, the green-house effect is more pronounced for earth’s surface than florist’s greenhouse.