Book cover for College Physics Explore and Apply

College Physics Explore and Apply

Eugenia Etkina; Alan Van Heuvelen; Gorazd Planinši?

ISBN #9780134601823

2nd Edition

2,244 Questions

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46,660 Students Helped

Homework Questions

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Summary

Learning Objectives

Key Concepts

Example Problems

Explanations

Common Mistakes

Summary

This section on Newtonian Mechanics covers the foundational principles that govern the motion of objects. It emphasizes the importance of correctly identifying a system and its environment, constructing accurate free-body diagrams, and systematically applying Newton’s three laws. Newton’s second law provides the quantitative relationship between net force, mass, and acceleration, while the third law ensures that interaction forces occur in equal and opposite pairs. Understanding inertial reference frames is critical to correctly analyzing physical phenomena, as demonstrated by various experiments and practical applications such as elevator readings and auto safety designs.

Learning Objectives

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Key Concepts

CONCEPT

DEFINITION

Atomic Physics

The study of atomic models and structure, detailing the evolution from classical orbit models (e.g., Bohr’s model) to quantum mechanics with quantized energy levels, quantum numbers, the uncertainty principle, and tunneling.

Example Problems

Example 1

$*$ In Figure $P 3.1$ you see unlabeled force diagrams for balls in different situations. Match the diagrams with the following descriptions. (1) A ball is moving upward after it leaves your hand. ( 2) You hold a ball in your hand. ( 3 ) A ball is falling down. (4) You are throwing a ball (still in your hand) straight up. (5) You are lifting a ball at a constant pace. Explain your choices. Label the forces on the diagrams.

Example 2

Draw a force diagram (a) for a bag hanging at rest from a spring; (b) for the same bag sitting on a table; and (c) for the same bag that you start to lift so it moves up faster and faster.

Example 3

For each of the following situations, draw the forces exerted on the moving object and identify the other object causing each force. (a) You pull a wagon along a level floor using a rope oriented horizontally. (b) A bus moving on a horizontal road slows down in order to stop. (c) You lift your overnight bag into the overhead compartment on an airplane.

Example 4

You hang a book bag on a spring scale and place the bag on a platform scale so that the platform scale reads $25.7 \mathrm{N}$ and the spring scale reads $17.6 \mathrm{N}$. (a) Draw a force diagram for the book bag to represent the situation. (b) What is the magnitude of the force that Earth exerts on the bag?

Example 5

A block of dry ice slides at constant velocity along a smooth, horizontal surface. (a) Construct a motion diagram. (b) Draw position- and velocityversus-time graphs. (c) Construct a force diagram for the block for three instants represented by dots on the motion diagram. Are the diagrams consistent with each other?

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Step-by-Step Explanations

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Common Mistakes

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