Maharashtra State Board Class 6 Science Work and Energy Textbook Exercises and Extra Question and Answers.
Fill in each blank with the appropriate term from the brackets.
(a) A bucketful of water is to be drawn from a well. Work will be done when a force is applied to do this, because there will be a displacement of water. (displacement, work, force)
(b) If a ball is dropped on the sloping roof of a house, it acquires kinetic energy and falls on the ground. That is, transformation of potential energy into kinetic energy takes place. (kinetic, potential, motion)
(c) You might have seen some beautiful fireworks during Diwali. It is an example of transformation of chemical energy into light energy. (light, atom, chemical, solar)
(d) The solar cooker is an application of the heat energy of the sun, while solar cells, solar lamps are applications of the light energy of the sun. (light, chemical, heat)
(e) One laborer carried four pans of road metal through a distance of 100 meters. If he carries two pans of road metal through a 200-meter distance, more work will be done. (equal, more, less)
(f) The capacity that an object has for doing work is called energy. (energy, displacement, force)
Match the pairs.
| Group ‘A’ | Group ‘B’ |
| (1) Rolling object | (c) Kinetic energy |
| (2) Food | (e) Chemical energy |
| (3) Stretched bow | (d) Potential energy |
| (4) Sunlight | (a) Heat energy |
| (5) Uranium | (b) Atomic energy |
Can you tell ?
(a) When can we say that displacement has taken place ?
(a) Displacement is said to have taken place when an object moves from one position to another, changing its location.
(b) What should be taken into account for measuring work ?
(b) For measuring work, you should take into account the force applied to an object and the displacement of that object in the direction of the force. The formula for work is Work = Force × Displacement × cos(θ), where θ is the angle between the force and the displacement vectors.
(c) What are the various forms of energy ?
(c) The various forms of energy include mechanical energy (such as potential and kinetic energy), heat energy, light energy, sound energy, chemical energy, and atomic energy.
(d) Describe one natural chain of transformation of energy.
(d) One natural chain of transformation of energy is the water cycle. Water evaporates due to the heat of the sun, forms clouds, and then falls as rain. The rainwater flows into rivers and is stored in reservoirs at a height, containing potential energy. When the water falls from a height, it transforms into kinetic energy, which can be harnessed to produce electricity through turbines. This electricity can further transform into various other forms of energy for use in homes.
(e) Why should we save energy ?
(e) We should save energy because it helps to conserve natural resources, reduce environmental pollution and greenhouse gas emissions, lower energy costs, and ensure a sustainable future for generations to come.
(f) What is ‘green energy’ ?
(f) ‘Green energy’ refers to energy sources that have a minimal environmental impact and are considered environmentally friendly. These sources often include renewable energy forms like solar, wind, hydroelectric, and geothermal energy.
