The Machine Age Class 5 Notes SST

Introduction

• People have always faced problems in completing their tasks.
• Sometimes they didn’t have enough energy, so they created machines to help them.
• Over time, many machines were invented to help society.
• In the old times, people used wood, stone, and bones to make tools like hammers and axes.
• The invention of the wheel was very important back then.
• As people discovered materials like copper and iron, they made things like pots and weapons.
• These inventions made life easier for everyone.

What is a Machine?

• A machine is a tool that helps make work easier by replacing or reducing human or animal effort.
• Machines help us complete tasks more easily.
• Some simple machines are:
  1. Lever: A crowbar used to lift a heavy object with less effort.
  2. Wedge: An axe used to split wood by focusing force on a single point.
  3. Wheel: A rolling suitcase makes it easy to carry heavy luggage.
  4. Pulley: A well's pulley system helps lift water from a bucket easily.
  5. Screw: A screwdriver is used to turn screws and hold things together tightly.

Sources of Energy

• In the past, people used manpower, animal power, and wind power (in boats) as energy sources.
• In 1769, James Watt introduced steam power for water pumps.
• Steam power was later used in machines like railway engines and ships.
• People started using steam power instead of relying on human and animal energy.
• Steam power was created by burning wood or coal.
• Wood came from forests, and coal was mined from the earth.
• Burning wood and coal released harmful gases like carbon dioxide, but people didn’t think about the environment back then.
• Wood and coal are limited resources, meaning they can run out.
• Early ships used wind power to sail, but later, steam engines were added to move ships without sails.

Petroleum

• Crude oil, also called petroleum, was discovered by ancient people from surface seepage.
• Petroleum was used for building roads, as lamp oil, and for painting ships.
• It comes from plants and animals that lived in the water millions of years ago.
• Over time, their remains turned into petroleum through natural processes.
• Today, petroleum has replaced coal as the main fuel for heating homes and industries.
• Products made from petroleum include petrol, diesel, kerosene, and many chemicals used for plastics, rubber, soaps, paints, and more.
• Petroleum is a limited resource, which means it can run out.
• The discovery of petroleum led to many new inventions like automobiles, airplanes, and diesel engines for trains and ships.
• Between the 18th and 20th centuries, petroleum helped create machines and electric power where hydroelectricity wasn’t possible.
• Currently, electricity is made by burning coal, diesel, or using hydroelectric power.
• Like coal, burning petroleum releases harmful gases like carbon dioxide, which cause environmental problems.

Alternative Sources of Energy

Energy sources have changed over time from:

• Animal energy → Coal → Petroleum → Atomic energy.

Current major energy sources include:

• Steam, gas, petrol, diesel, and electricity.
• In some places, animal energy is still used.

Alternative energy sources:

• Wind energy: Uses wind to run windmills for electricity and charging batteries.
• Solar energy: Uses the sun's energy for cooking, heating water, making electricity, and lighting.
• Hydrological energy: Uses water to generate power.