Physics Exam 1 Flashcards

Dimensions and Units

• Dimension: Categories of measurable quantities (e.g., mass, length, time).
• Unit: Specific ways to measure dimensions (e.g., kilograms, meters, seconds).

Displacement and Velocity

• Displacement: Calculated as ( \Delta X = X_f - X_i ).
• Average Speed: Total distance covered divided by total time.
• Average Velocity: Defined as displacement divided by time.
• Speed vs. Velocity: Speed is the absolute value of velocity.

Kinematics and Acceleration

• Constant Velocity: Can be represented by ( V = \Delta X/t ).
• Acceleration: Given by ( a = \Delta V/t ) and can be understood through graphical representation (slope of velocity graph).
• When Slowing Down: Occurs when velocity approaches zero from either side, indicated by different signs for velocity and acceleration.

Vector Addition and Subtraction

• Vector Addition: Implemented by drawing vectors tip-to-tail; use scale drawings for displacement and angles.
• Vector Subtraction: Involves adding the negative of a vector.

Kinematic Equations

• Constant Velocity Kinematic Equation: ( X_f = X_i + V_f ).
• Constant Acceleration Kinematic Equation: ( X_f = X_i + V_i t + \frac{1}{2} A t^2 ).

Examples in Motion

• Fish Leaping: Initial velocity calculated using ( V_f^2 = V_i^2 + 2aD_y ) leading to ( V_i \approx 3.95 , m/s ).
• Horizontal Leaps: Sperm whale example showing distance covered due to vertical height using ( u^2 \sin(2\theta) / g ).

Understanding Graphs

• Velocity on Position Graphs: The slope represents velocity.
• Acceleration on Velocity Graphs: The slope represents acceleration.

Calculating Distances and Times

• Falling Object: Time derived from ( t = \sqrt{2h/g} ).
• Subtle Differences: Distances traveled under different conditions (sober vs. drunk driving).

Significant Figures

• Rules of Significant Figures: Non-zero digits are significant, zeros between significant figures are significant, and final zeros after the decimal point are also significant.

Special Cases

• Toward Zero: A negative acceleration with a positive velocity indicates slowing down, and vice versa.
• Height and Speed: The relationship between height of jumps and initial speed (e.g., fox jumping).

Miscellaneous

• Acceleration of a Chipmunk: Can be calculated based on changing velocity over time.
• Ball Toss: The point of slowest speed during trajectory is at the peak.

Component Vectors

• Magnitude Calculation: A vector can be expressed with both ( x ) and ( y ) components.
• Components Representation: A vector defined either by magnitude and angle or by its components.

Projectile Motion

• Ball Trajectory: The maximum height reached corresponds to the minimum speed point in its arc.

General Principles

• Effects of Friction: After an initial powered acceleration, any friction leads to a deceleration.

Advanced Concepts

• Magnitude of Vector: The formula ( \sqrt{x^2 + y^2} ) can be used for magnitude determination.

Practical Applications

• Real-Life Examples: Evaluation of how various conditions (e.g., angle of launch, initial height) affect the outcome of a physical scenario.