13. Complete Activity 10.13 (Page 121).
• Sit in small groups.
• Discuss the various ways of energy conversion in nature.
• Discuss following questions in your group:
(a) How do green plants produce food?
(b) Where do they get their energy from?
(c) Why does the air move from place to place?
(d) How are fuels, such as coal and petroleum formed?
(e) What kinds of energy conversions sustain the water cycle?
Answer:
Various ways of energy conversion in nature
(i) Photosynthesis: During photosynthesis, green plants use the energy of the sun to form glucose from carbon dioxide and water. Glucose is a form of chemical energy.
(ii) Respiration: Organisms break down energy stored in glucose to produce energy that the body uses.
(iii) Wind Movement and Ocean Currents: The energy of the sun heats up the surface of the earth unevenly, which drives wind movement and ocean currents.
(iv) Water Cycle: The sun’s heat evaporates water from water bodies. This water rises to form clouds and water returns to the earth’s surface in the form of precipitation.
(v) Geological Processes: The internal heat of the earth causes tectonic plates to move and this results in phenomena like volcanic eruptions and formation of mountains.
(vi) Formation of Fossil Fuels: Through billions of years dead and decaying organic matter deep inside the earth have been converted into fossil fuels due to intense heat and pressure. These fossil fuels are a source of chemical energy.
(a) How do green plants produce food?
Green plants produce food by photosynthesis. During photosynthesis, plants use sunlight, water, and carbon dioxide to produce glucose (a type of sugar) and oxygen.
(b) Where do they get their energy from?
They get energy from the sun. Sunlight provides the energy necessary to power the chemical reactions that convert carbon dioxide and water into glucose and oxygen.
(c) Why does the air move from place to place?
The sun heats up the surface of the earth unevenly. This difference in temperature creates high-pressure and low-pressure areas. This results in movement of air from place to place.
(d) How are fuels, such as coal and petroleum formed?
Through billions of years dead plants and animals buried deep inside the earth have been converted into fossil fuels due to intense heat and pressure. Over time, the organic matter undergoes chemical transformations, eventually turning into fossil fuels like coal and petroleum.
(e) What kinds of energy conversions sustain the water cycle?
The water cycle involves several energy conversions:
- Solar energy heats the Earth’s surface, causing water to evaporate from water bodies.
- This evaporated water vapor rises into the atmosphere, cools and condenses to form clouds. This phase change releases latent heat energy.
- When clouds become saturated with water vapour, precipitation occurs in the form of rain, snow, or hail, converting gravitational potential energy into kinetic energy.
- As water flows downhill, gravitational potential energy is converted into kinetic energy.
“• Sit in small groups.
• Discuss the various ways of energy conversion in nature.
• Discuss following questions in your group:
(a) How do green plants produce food?
(b) Where do they get their energy from?
(c) Why does the air move from place to place?
(d) How are fuels, such as coal and petroleum formed?
(e) What kinds of energy conversions sustain the water cycle?” – Solved.
Related Links:
Solution to Activity 10.1
Solution to Activity 10.2
Solution to Activity 10.3
Solution to Activity 10.4
Solution to Activity 10.5
Solution to Activity 10.6
Solution to Activity 10.7
Solution to Activity 10.8
Solution to Activity 10.9
Solution to Activity 10.10
Solution to Activity 10.11
Solution to Activity 10.12
Solution to Activity 10.13
Solution to Activity 10.14
Solution to Activity 10.15
Solution to Activity 10.16
Solution to Activity 10.17
Solutions to Chapter 10 Work and Energy
