ENERGY
Source of energy
Sources of energy are systems which contain energy in different forms. They can be classified into renewable and non-renewable.
a) Non- renewable sources
Non-renewable energy sources are finite energy sources. Fossil fuel is an energy. Which is found in the remains of once living things is good example. It includes coal, natural gas and oil. Coal and coke used
b) Renewable energy sources
Renewable energy sources are infinite of replenish energy sources. Energy sources which are not day from the earth are called alternative energy sources. These include sun, tides,wind wood etc. Wood and charcoal still used in many countries for heating homes and cooking.
Types of energy
Energy is something that is important to do work. We use chemical energy from food to do work.For example, when we lift a weight, drag a heavy sack across the floor, or push a lawnmower, we are doing work. The amount of work done depends on the energy that have stored in our muscles.There are several types of energy that can be used to do work. Living things, machines, and electrical appliances convert energy form one type into other form. Some forms of energy are:
Chemical Energy
Chemical energy is energy that is produced as a result of a chemical reaction. For example, when fuel burns in an engine, when a human body uses food, or when a battery produces electricity.
Electrical Energy
Electrical energy is energy due to electrical charges moving. For example, electric current in a wire. Batteries and generators are used to produce electricity
Potential Energy
This is an energy stored in materials that have been stretched. For example, tightly wound clock,or a stretched elastic band. This is thought of as strain or spring energy.
Energy
Gravitational energy is an energy, stored in materials that been moved upwards, so that they can fall down. For example, a skier at the top of mountain, a diver at a high diving board.
Sources of Energy
We get a lot of the energy we need by burning fuel. The energy is released by a chemical reaction called combustion. Common fuels are: Wood and charcoal still used in many countries for heating homes and cooking; coal and coke, used in homes and power stations, natural gas, used in homes,factories, and power stations; and oil products which are used vehicles, for heating homes and in power stations.
Other Sources
Energy, which is found from the remains of once living things, is called fossil fuels. Energy sources, which are not dug from the earth, are called alternative energy sources. They use natural sources such as the sun, the tides and the wind. Because these things are able to supply energy for millions of years they are called renewable energy sources.
Wind Power
Old windmills in different countries show that we can use energy from the wind. The old mills were used to grind cereals, but when the wind did not blow, the work had to stop. The fact that the wind does not blow steadily is still a problem.
Hydro Power
About 200 years ago mills and factories were built near to fast flowing rivers. The moving water was used to turn a waterwheel which then drove machinery. Hydroelectric power stations have proved every successful but they are expensive to build.
Solar Energy
The calculator show here is solar powered. The solar cell uses energy in light to produce a very small amount of electricity. This is enough to make the calculator work and so no batteries are needed. Cells like these are used to generate electricity for satellites in space.
The earth gets more than enough energy from the sun to meet all its energy needs. If we can trap and use this energy, we would not need to burn fuels. Scientists and engineers are trying to find the best way to do this.
Summary
• Energy is something used to do work.
• Energy exists in different forms
• Energy sources can be renewable and non-renewable
Fossil fuels are good sources of energy
FORCE, GRAVITY AND SIMPLE MACHINES
Force is a very important part of our world. We use force and its actions when we work and play. If there weren’t any forces, we couldn’t play ball or ride a bicycle. Forces are all around us.
Sometimes forces act together, and sometimes they act against each other. Forces are needed to start or change any motion. Force is either pushing or pulling.
Effects of force
Force is needed to move or to stop an object. Thus, changing the motion of an object or stopping it is the effect of a force. In addition to this force, it can change the shape and size of a body or object. Some examples of effects of a force are:
- Put a box on a table and watch it for a while. It cannot move from its place, unless you push or pull it.
- Take a flat wooden plank and make an inclined plane as shown in the picture. Put on top of the plank a piece of wood. Watch it slide downwards. When you put your hand at the bottom it will stop the motion.
- Take a spring and attach over it different weights as shown in the picture. The heavier the weight the further the spring will stretch. Try this experiment by using rubber bands.
Measuring Force
When the force applied on a body increases, its speed or its size will change. Therefore, the speed of the body or its change in size will help us to measure force.By using the increase in size of a spring, we can measure weight. This type of weight measuring instrument is known as a spring balance or Newton meter. The unit of weight or force is a Newton.
GRAVITY
When we drop stones in the air, they fall very rapidly. Under suitable conditions all bodies accelerate towards the earth at the same rate. We call this: acceleration due to gravity.
Weight
What is weight? Weight means the pull of gravity from earth on an object. Therefore, weight is force. Don’t forget that weight and mass are different physical quantities.
Spring Balance
Weight is measured by using the spring balance (Newton meter) or by using Newton meter we can measure the pull of the earth on an object.
Mass
The weight of a body depends on the mass of the body. Mass is the amount of matter in a body.
The unit of mass is a kilogram. The weight of a 1-kilogram object is approximately 10 Newton
based on this relation; one can determine the weight of any object.
For example – if the mass of a body is 10 kilograms, then its weight is 10 x 10 = 100 Newton.
Simple machines
If your teacher asked you to list some machines, you might say lawn mower, tractor or blender. A simple machine is made of only one part. Machines are used to perform work; by applying a small force to lift a large weight; to lift a weight faster, or to change the direction of the force.One simple machine cannot give all three the advantage at the same time. One simple machine can be force multiplier or a speed multiplier.
When a body is lifted to a certain height by a simple machine, we can say that the machine does work. The weight which is lifted by a simple machine is known as the load, and the force applied to lift the weight (load) is known as effort. The advantage of a simple machine is determined by the ration its load and effort.
Lever
A lever is a machine made of a bar or that turns on a point. The point on which a leaver turns is called the fulcrum. The force, or effort, is used on one end of the lever. This force moves the object that is attached to the other end. This object is the load. The closer the fulcrum is to the load, the easier the load is to lift. According to the position of load, effort and fulcrum levers are divided in to three orders.
-First order lever is the lever system where the fulcrum is between the load and effort. As an example we can take crowbar.
- Second order lever in the second order, the lever is between the fulcrum and the effort. As an example, we can take wheelbarrow.
- Third order lever the effort is placed between the fulcrum and load. The fishing rod is an example of third order lever.
Pulley
Pulleys rotate on an axis. Pulleys are used to changing the direction or amount of force. Pulleys are often used for lifting heavy objects. In rural areas people are used to pulling out water from wells.
Inclined plane
The ramp is a third kind of simple machine called an inclined plane. An inclined plane is a machine made of a slated surface. Pushing the box up an inclined plane takes small force. Lifting the box straight up takes a larger force, but the distance the box is pushed across the inclined plane is longer.
Part I. Please answer the following questions
1. What is energy?
_______________________________________________________________
2. List the different forms of existence of energy
_________________ ______________________ ________________________
3. Where does the energy to lift a weight come from/?
________________________________________________________________
4. What are renewable energy sources?
_________________________________________________________________
5. What is fossil fuel?
Part II. Match column ‘A’ with column ‘B’ in the following
A B
1. Chemical energy a. energy from the sun
2. Electrical energy b. energy from dry cell
3. Gravitational energy c. energy in electrical stove
4. Solar energy d. energy of a moving body
5. Sound energy e. energy of a compressed spring
f. energy of a sound wave
Part III. Circle the correct answer
1. Which one of the following is a chemical energy?
a. Energy in food c. Energy in a dry cell
b. Energy in petroleum d. all
2. When a ball is taken from the ground to a certain height, the ball will gain.
a. Kinetic energy c. Gravitational energy
b. Electrical energy d. Natural gas
3. Which one of the following is a renewable energy source?
a. Wind power c. Fossil fuel
b. Oil d. Natural gas
4. The ultimate source of energy for living things is
a. Food c. Sun
b. Fossil fuel d. Wind power
I. Answer the following questions accordingly.
1. What is chemical energy? Which form of energy is most widely used by human being nowadays?
2. Write down the different forms of energy is much as you can.
3. What are the sources of energy?
4. What are non-renewable energy sources?
5. What are the alternate sources of energy?
II. Write down the sources of the indicated energy?
a. Chemical energy ______________________________________________
b. Electrical energy _______________________________________________
c. Gravitational energy ___________________________________________
d. Solar energy ___________________________________________________
e. Sound energy __________________________________________________
III. Choose the most appropriate words among the given alternatives
1. Which of the following provides chemical energy?
a) Food C) dry cell
b) Rolling ball d) a and c
2. When a ball is taken from the ground to a certain height, the ball will lose its
a) Potential energy c) Gravitational energy
b) Kinetic energy d) Heat energy
3. The most widely used of energy by human being is
a) Potential energy c) Chemical energy
b) Solar energy d) Wind energy
SECTION A
FILL IN THE BLANKS Marks
1 The wearing away of rocks is called _________________.
2 The clearing of forests by humans is called ____________________.
3 ______________ is the major mineral present in Limestone.
4 _______________ is a sedimentary rock formed when layers of clay harden.
WRITE TRUE OR FALSE
5 Fossils are found in metamorphic rocks. (Answer :____________)
6 Wind erosion is greatest in desert. (Answer :____________)
7 A Rock contains one or more minerals (Answer :____________)
8 Ploughing of farm land reduces soil erosion (Answer :____________)
MULTIPLE CHOICE QUESTIONS
9 A sedimentary rock formed from plants
(a) Chalk (b) marble (c) coal (d) limestone
Answer : ---------
10 Quartzite is a metamorphic rock formed from ________________
(a) Marble (b) sandstone (c) conglomerate (d) Basalt
11 Which among the following will reduce wind erosion?
(a) Shelter belts (b) embankments (c) step farming (d)ploughing
Answer : ---------
12 Mica is a/an ______________
(a) Igneous rock (b) sedimentary rock (c) metamorphic rock
(d) mineral
Answer:----------:
SECTION B
ANSWER IN ONE WORD OR ONE SENTENCE
1 What are fossils?
___________________________________________________________________
___________________________________________________________________
2 How are metamorphic rocks formed?
___________________________________________________________________
___________________________________________________________________
3 How does terrace farming helps in reducing soil erosion?
___________________________________________________________________
___________________________________________________________________
4 How does soil erosion affects the agriculture?
___________________________________________________________________
___________________________________________________________________
ANSWER THE FOLLOWING IN TWO SENTENCES
5 Write any TWO ways in which soil is useful for organisms
6 How is petroleum formed? Write any two uses of it.
Please click on below link to download CBSE Class 5 Science Worksheet Set E
