Physics Exam 1 Flashcards

Questions and Answers

What is the difference between dimension and unit?

Dimension: a physical concept; Unit: an abstract idea

Dimension: a single measurement; Unit: multiple measurements

Dimension: non-measurable aspects; Unit: measurable aspects

Dimension: categories like mass and length; Unit: measurement methods like kilo and meters (correct)

What is displacement?

DX = Xf - Xi

What is average speed?

Total distance divided by total time

What is average velocity?

Displacement divided by time Signup and view all the answers

How does speed relate to velocity?

Speed is the absolute value of velocity Signup and view all the answers

What is constant velocity?

V = DX/t Signup and view all the answers

What does velocity represent on position graphs?

Slope Signup and view all the answers

What does acceleration represent on velocity graphs?

Slope Signup and view all the answers

What is acceleration?

DV/t Signup and view all the answers

An object is slowing down when its velocity is approaching ___ from both sides.

0 Signup and view all the answers

When does a negative acceleration occur?

When speeding up leftward Signup and view all the answers

When does a positive acceleration occur?

When slowing down leftward Signup and view all the answers

What indicates that something is slowing down?

When velocity and acceleration have different signs Signup and view all the answers

What is the kinematic equation for constant velocity?

Xf = Xi + Vf Signup and view all the answers

What is the kinematic equation for constant acceleration?

Xf = Xi + Vit + (1/2)At^2 Signup and view all the answers

What is the velocity of a fish that jumps to a height of 0.8 m?

3.95 m/s Signup and view all the answers

How do you find the addition of vectors?

Draw vectors tip-to-tail and use scale drawing Signup and view all the answers

What is the method for subtracting vectors?

Add the negative of the vector Signup and view all the answers

What is the equation for falling object time?

t = sqrt(2h/g) Signup and view all the answers

What are the Significant Figure Rules?

<ol> <li>Non-zeros are significant; 2. Zeros between figs are significant; 3. Final zeros after decimal are significant; 4. Zeros only for decimal placement are not significant without a decimal.</li> </ol> Signup and view all the answers

Are all equations that have consistent units valid?

False Signup and view all the answers

What is Jack's average velocity if he swims 9 lengths of a 25 m pool in 157.3 s?

0.159 m/s Signup and view all the answers

How much further does a drunk driver travel before brakes compared to a sober driver?

17.9 meters further Signup and view all the answers

What is the average acceleration of a chipmunk moving from -1.41 m/s to 1.99 m/s in 2.55 s?

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What is the magnitude of vector A if its x-component is -10.65 and y-component is 6.45?

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What is the angle of vector A if its components are equal?

45 degrees Signup and view all the answers

At what point does a ball tossed into the air have the smallest speed?

At the highest point in its flight Signup and view all the answers

What are the two ways to specify a vector?

Magnitude and angle, or components Signup and view all the answers

Study Notes

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.

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Description

Prepare for your physics exam with these flashcards covering essential concepts. Learn the differences between dimensions and units, and understand key terms like displacement, average speed, and average velocity. Ideal for reviewing foundational physics topics.