Business and finance

A successful business makes good decisions on what products to make, what products to sell, and how

its products compare to other products. A basic understanding of physics is useful for anyone who must

make decisions based on technology. For example, a company that produces cars needs to create cars

that use the latest technology, and are competitive with technology offered by other car manufacturers

(Figure 1.16). Like all technology, new technology in cars is based on physics. For example, the

introduction of air bags (Chapter 12) and antilock brakes (Chapter 4) both made cars safer to drive by

changing the forces acting on a car, on the road and on passengers in the car. These new technologies

were expensive to develop and many different designs were proposed. Car companies needed physics

to decide which designs offered the best combination of performance and cost.

Physics is also useful in business for its approach to analysis and problem solving. A person who learns

physics also learns many very effective ways to analyze data and draw conclusions about what is

happening. Good business decisions almost always consider data that describes the various options a

company can take. For example, business data might include the cost of buying paint and paying the

employees who paint cars. In order to decide whether to use two colors or one to paint a new car, all of

the data should be analyzed, so the company knows the cost of the decision and the potential benefits. A real-life business is described by many thousands of bits of data exactly like this. Physics is one of the

Very best ways to learn how to analyze data and draw conclusions (Figure 1.17).

Businesses rely on technology, such as computers, heating systems, lighting systems, and electricity.

Each of these technologies includes many choices and each choice has different benefits and

limitations. For example, a company might decide to use incandescent light bulbs because the people

making the decision like the warmer light of an incandescent bulb. Fluorescent light bulbs often have a

colder, bluish light. However, incandescent light bulbs use much more energy than fluorescent light

bulbs and so may increase the use of air conditioning in order to remove the heat they generate.

Electricity, light, and heat are all described by physics (Chapters 16, 19, and 26). A wise business leader

makes decisions that assess the trade-offs between different choices of technology. These trade-offs

almost always require a basic understanding of physics to interpret correctly.

Art, music, and food

The creation and perception of light and color is important to anyone who paints, takes pictures, makes

movies, or works with any type of image. The human eye sees three basic colors: red, green, and blue.

Other colors are made by combining different proportions of red, green, and blue. Physics describes

how light is made and how color is created (Chapter 16).

Today, we are accustomed to sharing images through such media as photographs, videos, books, and

magazines. The reproduction of an image is another area where physics is used. The images you see in

photographs or magazines are printed in four special colors of ink: cyan, magenta, yellow, and black. A

printer can create almost any color by using a combination of just these four colors (Figure 1.18). The

exact colors of the four inks are determined by the physics of light (chapter 16).

All types of video cameras, digital cameras, or film cameras use optics. Optics is the physics and

technology of working with light (Chapter 17). Everyone who produces video uses physics knowledge

every time they adjust the lights on a set or change the color balance of a camera. In addition, many

special effects are created with devices such as mirrors, lenses, and prisms. People who do special

effects need to understand the physics behind how these devices work in order to use them effectively.

Almost everyone enjoys listening to musical sound. Sound is a traveling vibration in the air that is

created by vibrating strings, speakers, or other devices. The creation of sound and the movement of

sound are part of physics (Chapter 15). The physics of sound is used by people who set up concerts,

design musical instruments, play music on every variety of instrument, and even by people who design

buildings where musicians will perform. The technology of electronic amplification and recording of

music is also based on physics (Figure 1.19 and Chapter 24).

Even everyday activities such as cooking use physics. You are using physics when you set the

temperature of an oven hotter because you want to cook something faster. Food cooks when its

temperature rises. Temperature rises because heat energy flows from the hotter oven into the cooler

food. Increasing the temperature of the oven causes heat energy to flow from the oven into the food

faster, which is why it cooks faster. Temperature and the process of heat flowing are described by

physics (Chapters 25 and 26).