Basic Physics

A Self-Teaching Guide

Karl F. Kuhn, Frank Noschese

• Éditeur: Jossey-Bass
• Année: 2020
• ISBN:
  9781119629894
• Édition: 3
• Sujet: Sciences physiques
• Sous-sujet: Physique

Learn physics at your own pace without an instructor

Basic Physics: A Self-Teaching Guide, 3rd Edition is the most practical and reader-friendly guide to understanding all basic physics concepts and terms. The expert authors take a flexible and interactive approach to physics based on new research-based methods about how people most effectively comprehend new material. The book takes complex concepts and breaks them down into practical, easy to digest terms.

Subject matter covered includes:

• Newton's Laws
• Energy
• Electricity
• Magnetism
• Light
• Sound
• And more

There are also sections explaining the math behind each concept for those who would like further explanation and understanding. Each chapter features a list of objectives so that students know what they should be learning from each chapter, test questions, and exercises that inspire deeper learning about physics.

High school students, college students, and those re-learning physics alike will greatly enhance their physics education with the help of this one-of-a-kind guide. The third edition of this book reflects and implements new, research-based methods regarding how people best learn new material. As a result, it contains a flexible and interactive approach to learning physics.

1
Motion

Physics deals with quantities that can be measured. Thus, you won't find concepts such as honesty, love, and courage as primary topics of discussion in a physics book. As you proceed through your study of physics, you will find that every one of the measurable quantities that is discussed can be specified in terms of only four basic dimensions: mass, length, time, and electric charge. In this chapter, we will begin a study of the first three of these.

---

OBJECTIVES

After completing this chapter, you will be able to

• define speed;
• calculate speed, distance, or time, given the other two values;
• calculate acceleration, given initial and final velocities and the elapsed time;
• use a motion diagram to model the motion of an object;
• state the value of the acceleration of gravity;
• given an initial velocity, calculate the distance an object will fall in a given time;
• differentiate between speed and velocity;
• distinguish between scalar and vector quantities, giving an example of each;
• use the graphical method to add vectors;
• identify and classify (as to acceleration and velocity) each of the two components of projectile motion.

---

SPEED

Speed is defined as the distance traveled divided by the time of travel. Thus, if you travel 12 miles in 3 hours, the average speed is 4 mi/hr (mi/hr or mph).*

1. If an elephant runs for half an hour at a speed of 6 mi/hr, what distance does it cover? ______________________
2. A box is on a conveyor belt. What is the speed of the box if it moves 15 ft in 10 seconds? _____________________
3. Using the symbols s, d, and t (for speed, distance, and time), write a formula for speed. _____________________

Answers: (a) 3 miles; (b) 1.5 ft/s; (c) s = d/t

In practice, we usually use the symbol v to represent speed (because of the similarity between speed and velocity, a concept that will be discussed later). For an object that moves with constant speed, the defining equation for speed is:

Here v is the speed and d is the distance the object travels after time t has elapsed.

The above equation holds true for objects that move with constant speed (like a car in cruise control). However, if the speed of the object changes while moving, the above equation gives us just the object's average speed. For example, if it takes you 30 minutes to drive to a friend's house 12 miles away, your average speed is 24 mi/hr. That doesn't mean your speed was 24 mi/hr for the entire trip. Due to traffic lights, road speed limits, and traffic conditions, there were times during your trip when you traveled slower than 24 mi/hr and times you were traveling faster. An average speed doesn't tell us how an object is moving at any particular instant. Only when an object is moving with constant speed does its average speed equal its actual speed.

1. What is the average speed of a car that covers 250 miles in 5 hours? _________________________
2. What is the average speed a plane flying 2,600 miles from New York City to Los Angeles in 6.5 hours? _____________________
3. Physicists use the SI system (Système International), which uses meters as its basic unit of length. (For reference, 1 m is approximately equal to 3 ft.) If you walk with a speed of 2 meters per second (m/s), how far do you walk in 12 seconds?

Answers: (a) 50 mi/hr; (b) 400 mi/hr; (c) 24 m

ACCELERATION

As a car gains speed, we say that it accelerates. The change in speed divided by the time it takes to make the change is c...

Table des matières

• Cover
• Table of Contents
• Acknowledgments
• To the Reader
• 1 Motion
• 2 Force and Newton's Laws of Motion
• 3 Conservation of Momentum and Energy
• 4 Gravity
• 5 Atoms and Molecules
• 6 Solids
• 7 Liquids and Gases
• 8 Temperature and Heat Energy
• 9 Change of State and Transfer of Heat Energy
• 10 Wave Motion
• 11 Sound
• 12 Diffraction, Interference, and Music
• 13 Static Electricity
• 14 Electrical Current
• 15 Magnetism and Magnetic Effects of Currents
• 16 Electrical Induction
• 17 Electromagnetic Waves
• 18 Light: Wave or Particle?
• 19 The Quantum Nature of Light
• 20 Reflection, Refraction, and Dispersion
• 21 Lenses and Instruments
• 22 Light as a Wave
• 23 Color
• Appendix A: Scientific Notation: Powers of Ten
• Appendix B: The Metric System
• Index
• End User License Agreement