What Physics and Mechanics Are
What Is Mechanics?
Mechanics in one sentence
Mechanics is the branch of physics that studies motion and the forces that cause motion. In Newtonian mechanics, we describe objects using ideas like position, velocity, acceleration, mass, and force.
Why start here?
If you can describe how something moves and what pushes or pulls on it, you already have the core tools of classical mechanics.
The Basic Building Blocks
Core ideas
A first look at motion
Suppose a ball moves in a straight line. If its position changes by over time , its average velocity is . If velocity changes by , then average acceleration is .
Which quantity tells you how quickly velocity changes?
Acceleration is the rate of change of velocity.
Correct answer: Acceleration
In one sentence, what does mechanics study?
This is the central idea of mechanics.
Correct answer: Motion and the forces that cause motion.
How we will study mechanics
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Step 1: Describe motion using position, velocity, and acceleration.
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Step 2: Learn how forces affect motion.
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Step 3: Apply Newton’s laws to solve problems.
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Step 4: Use momentum, energy, and rotation to analyze more complex situations.