TOPIC 1: INTRODUCTION TO PHYSICS

Physics is often described as the study of matter and energy. It is concerned with how matter and energy relate to each other and how they affect each other over time and through space. Physicists ask fundamental questions: How did the universe begin? How and of what is it made? How does it change? What rules govern its behavior?

Concepts of Physics

Physics is the general scientific study of nature that aims to understand the behavior of the universe. It tries to explain how things happen around us or why they happen the way they do. For example, how does a car move from one point to another? Why do unlike poles of magnets attract? Why does a mango fall? How is a rainbow formed? And so on.

Physics uses concepts like force, energy, mass, and power to explain different phenomena. Energy, for example, may take the form of motion, light, or electricity. In this way, students of physics learn more about matter and energy and how they interact.

Therefore, physics is the study of the relationship between matter and energy.

The people who study and work professionally in this field are called physicists.

Physics is an experimental science that creates theories tested against observations of the natural world. Theories explain why things behave the way they do. This is why physicists insist on accurate measurements and a record of results during each experiment.

Once these results are expressed in precise mathematical forms, technologists use such data when designing devices such as radios, televisions, mobile phones, computers, and artificial satellites. All these inventions improve human life.

The Relationship between Physics and Other Subjects

Knowledge of physics is applied in other subjects. For example, the principles of electrostatics and the particulate nature of matter explain reactions in chemistry. Tools, implements, and farm machinery learned in agriculture, as well as the process of dating historical remains, are applications of physics.

Physics provides the basis for biology. Without space, matter, energy, and time—components that make up the universe—living organisms would not exist. Physicist Richard Feynman said that everything on Earth is made of atoms, basic units of matter, that constantly move. Since biology has its foundation in physics, it applies physical natural laws to the study of living organisms, according to Muskegon Community College. For instance, physics helps explain how bats use sound waves to navigate in the dark and how wings give insects the ability to move through the air. The American Physical Society notes that many flowers arrange their seeds or petals in a Fibonacci-like sequence to maximize exposure to light and nutrients. In some cases, biology helps prove physical laws and theories. Feynman states that biology helped scientists develop the law of conservation of energy.

Importance of Studying Physics

Why Study Physics?

1. Physics helps us understand how the world around us works, from can openers, light bulbs, and cell phones to muscles, lungs, and brains; from paints, piccolos, and pirouettes to cameras, cars, and cathedrals; from earthquakes, tsunamis, and hurricanes to quarks, DNA, and black holes. From the prosaic to the profound to the poetic.
2. Physics helps us organize the universe. It deals with fundamentals and helps us see the connections between seemingly disparate phenomena. Physics gives us powerful tools to express our creativity, to see the world in new ways, and then to change it.
3. Physics provides quantitative and analytic skills needed for analyzing data and solving problems in the sciences, engineering, and medicine, as well as in economics, finance, management, law, and public policy.
4. Physics is the basis for most modern technology and for the tools and instruments used in scientific, engineering, and medical research and development. Manufacturing is dominated by physics-based technology.
5. Physics helps you to help others. Doctors who don’t understand physics can be dangerous. Medicine without physics technology would be barbaric. Schools without qualified physics teachers cut their students off from a host of well-respected, well-paying careers.

Applications of Physics in Real Life

Discoveries in physics have led to various inventions that influence our lives.

1. At home: All tools and machinery we use at home to make work easier are made according to the laws of physics. These include crowbars, hammers, door handles, cutlery, hinges, car jacks, pulleys, tillage implements, and many others. For example, lifting a car to change its tires would be difficult without a car jack. Electrical appliances such as cookers, irons, heaters, electric lamps, and washing machines result from the application of physics knowledge.
2. Medical field: Many medical processes and machines rely on physics. Some machines are used in diagnosis and treatment of ailments and in sustaining patients’ lives through therapy. Examples include lasers, X-rays, incubators, ultrasound, and infrared machines. The knowledge used in handling and operating these machines is based on physics.
3. Source of energy: Some processes and machines help us obtain energy for daily use. These machines use various laws of physics to provide different forms of energy. For example, batteries and generators provide electrical energy used in radios and televisions. A car battery provides energy to start a car. When devices like bulbs are connected to these sources, they provide light energy.
4. Transport: The application of laws governing friction and frictional forces ensures that humans and animals can walk, run, and stop without falling. Vehicles such as cars, ships, airplanes, and trains move, brake, and stop because laws related to friction, flotation, and balance are observed. When these laws are ignored, ships sink and trains derail.
5. Communication: Devices used in communication systems such as telephones, modems, and televisions use cables, transmitters, and receivers to relay information. Physics knowledge is essential because these instruments use fiber optics and radio waves to transmit messages. Newspapers, letters, emails, fax messages, and SMS through mobile phones are reliable communication means, all requiring physics.
6. Entertainment: Physics enables people to enjoy leisure activities such as photography, digital appliances, exercise machines, and sports equipment.
7. Industry: Physicists have developed tools and processes resulting in advanced technological equipment and new discoveries. These include computer assembly and programs used in design; instruments like binoculars and telescopes; the ability to land on the moon and measure temperatures of celestial bodies.
8. In schools: Instruments and apparatus used in school laboratories are made through the application of physics knowledge and skills. These apparatus must meet universally accepted specifications and standards.

Physics in Daily Life

Driving a car requires a basic understanding of physics principles, whether the driver is aware of them or not. For instance, the balance of a car changes as it accelerates, decelerates, or turns. To keep the car on the road, the driver must anticipate these forces and adjust accordingly.

Understanding physics can also help when lifting heavy objects. For example, using simple machines such as inclined planes or levers makes lifting easier. Physicists study simple machines extensively and use their lessons to create increasingly efficient tools.

To stay warm in winter, people turn up the heat or use physics principles to make better use of existing heat. Heat flows via conduction, radiation, and convection; understanding these differences helps insulate a house better. For example, using ceiling fans intelligently can enhance convective heat flow to one’s advantage.