Maharashtra Board Class 6 Science Solution Chapter 11 – Work and Energy
Balbharati Maharashtra Board Class 6 Science Solution Chapter 11: Work and Energy. Marathi or English Medium Students of Class 6 get here Work and Energy full Exercise Solution.
|Maharashtra Class 6|
Work and Energy
1.) 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 motion and falls on the ground. That is, the 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 the 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 labourer carried fourpans of road metal through a distance of 100 metres . If he carries two pans of road metal through a200 metre distance equal work will be done.
(equal, more , less )
d.) The capacity that an object has for doing work is called energy.
(energy, displacement, force )
2.) Match the pairs.
Group ‘A’ Group ‘B’
1.) Rolling object a. Heat energy
2.) Food b. Atomic energy
3.) Stretched bow c. Kinetic energy
4.) Sunlight d. Potential energy
5.) Uranium e. Chemical energy
Group ‘A’ Group’B’
1.) Rolling object Kinetic energy
2.) Food Chemical energy
3.) Stretched bow Potential energy
4.) Sunlight Heat energy
5.) Uranium Atomic energy
3.) Can you tell?
a.) When can we say that displacement has taken place?
When there is a change in the position of some of the objects, then we can say that displacement has taken place. When there is displacement of an object by exerting a force on it, then it is said that work has been done.
b.) What should be taken into account for measuring work?
When there is a constant applied force, greater work is being executed when there is a great deal of displacement. To put it in another way, for measuring work, the extent of force that is exerted on an object and the displacement of that particular object must be taken into consideration.
c.) What are the various forms of energy?
Mechanical energy, heat energy, light energy, sound energy and chemical energy are the various forms of energy.
Mechanical energy – Mechanical energy may be defined as the energy that is used for the purpose of doing mechanical work. Potential energy and kinetic energy are the two different types of mechanical energy.
Potential energy may be defined as the energy that is acquired as a result of position and kinetic energy is obtained due to motion.
Heat energy – It is from the sun, that the earth obtains heat in an appropriate amount. In this way, an atmospheric temperature that is beneficial to the living things is maintained in a proper manner. So, heat is a form of energy and this energy is contained in sunlight. Heat is generated by burning fuel. In the kitchen, heat energy is used all the time. Calorie is the unit of heat.
Light energy – As we all know that, it is with the help of sunlight, the plants prepares their own food. It clearly indicates that, there is transformation of light energy into the energy in the food. This food is used by the plants and animals for the purpose of carrying out their work. This signifies that light is a form of energy.
Sound energy – Due to loud sound, the glass panes of windows might crack. Simultaneously, in order to regulate the movements of some toys, sound is used. This clearly indicates that there is execution of some work by sound. This means that sound is a form of energy.
Chemical energy – Chemical energy may be defined as the energy that is acquired through the process of chemical action.
d.) Describe one natural chain of transformation of energy.
It is through the process of photosynthesis, the plants makes their own food by using solar energy. The plant produces their food in the form of chemical energy. This food is used by animals which enables them to develop strength and muscle energy. Therefore, heat energy is produced in the body through the process of digestion.
e.) Why should we save energy?
In order to save money, it is essential to save the energy. We are all aware of the fact that, we have to pay huge electricity bill for using the energy. So if we limit the use of energy, then it will contribute in saving our money. It will also help in maintaining the cleanliness of our environment. If we limit the use of energy, then it will help in producing less quantity of energy that are generated from coal and petroleum which gives rise to pollution. So, if we use less energy, then it will help to curb the rate of pollution. The usage of this energy are mostly produced from coal and petroleum which are conventional sources of energy that means, these resources could not be replenished by natural procedure. So, if we are wasting the energy then we are in some waywasting these energy resources and therefore ,one day will arrive when there will be extreme shortage of these resources. So, it is essential to save energy because by saving energy we are in some ways preserving the non -renewable resources of energy. These points clearly indicates the importance of saving energy.
f.) What is ‘green energy ‘?
Green energy may be defined as the form of energy that prohibits the production of smoke and carbon gases as for instance , carbon monoxide or carbon dioxide. The energy that is obtained from the sun is one of the perfect example of green energy. Sunlight, wind and water are the different types of green energy.
g.) What are the non – conventional energy resources?
Non – conventional energy resources are the inexhaustible resources of energy and can be utilized in several forms in a continuous manner. The usage of these energy resources were limited in traditional times. In short, non -conventional energy resources are also called renewable energy resources that can be restored again through the natural procedure. Wind energy and solar energy are some of the relevant examples of non -conventional energy resources.
h.) Which forms of energy from the sun are used in solar energy devices?
The heat energy that is obtained from the sun are used in solar energy devices , as for instance, solar heater and solar cooker. In solar lamps, there is conversion of light energy into electrical energy. It is suitable for our everyday life purposes. In solar cells, which is also known as photovoltaic cell , solar energy is used for the purpose of producing electricity.
i.) Why should we maximize the use of non – conventional energy resources?
As the growth rate of our population is increasing in a rapid manner, so there is also an increased demand or requirements of the conventional energy resources. These energy resources are non- renewable in nature, which means it could not be replenished by any natural processes. So, as a result of which there will be a shortage of these non- renewable resources for our subsequent generations. So, it is extremely essential to enhance the use of non -conventional energy resources because they are inexhaustible natural resources and these resources can be obtained in a continuous manner. These resources are not subjected to depletion and they also does not create any form of pollution.
4.) Who is the odd -one -out?
1.) Diesel, crude oil, natural gas, wind
Wind is a non- conventional energy resource , so it is the odd one out, on the other hand, diesel, crude oil and natural gas falls under the category of conventional energy resources.
2.) A running car , hauling a log , a book kept on a table , picking up the school bag.
A book kept on a table does not depict any form of displacement, so it is the odd one out, on the other hand, a running car , hauling a log and picking up the school bag portrays some form of displacement.
3.) Sunlight, wind, waves, petrol
Petrol is the non- renewable source of energy , so it is odd one out, on the other hand, sunlight, wind and waves falls under the category of renewable sources of energy.
4.) Leaving the fan on in a vacant room, leaving the TV on while working, using AC during winter, putting off the light when going out.
Putting off the light when going out, depicts the action of saving energy, so it is the odd one out, on the other hand, leaving the fan on in a vacant room, leaving the TV on while working and using AC during winter portrays the action of wasting energy.
5.) Find out the types of energy from the following puzzle.