Physical Science Final

Motion and Forces Study Guide

Equations

  • Familiarize yourself with the following equations:

    • Change in Velocity:
      \Delta V = Vf - Vi

    • Net Force:
      F_{net} = m \cdot a

    • Force of Gravity:
      F_1 = mg

    • Acceleration due to Gravity:
      g = -9.8 ext{ m/s}^2

    • Average Speed:
      s = \frac{d}{t}

    • Momentum:
      p = mv

Motion Concepts

  1. Definitions:

    • Distance: The total length of the path traveled by an object.

    • Displacement: The change in position of an object; a vector quantity that includes both magnitude and direction.

    • Speed: A scalar quantity representing how fast an object is moving, calculated as distance over time.

    • Velocity: A vector quantity that includes both speed in a given direction; defined as displacement over time.

    • Acceleration: The rate of change of velocity over time; can occur when speed increases, decreases, or direction changes.

  2. Vector vs Scalar Quantities:

    • Vector Quantities:

      • Displacement

      • Velocity

      • Acceleration

    • Scalar Quantities:

      • Distance

      • Speed

    • Difference:

      • Vector quantities possess both magnitude and direction, whereas scalar quantities have only magnitude.

  3. Slope of a Position vs Time Graph:

    • The slope of a position vs time graph represents the velocity of the object. A steeper slope indicates a higher velocity.

  4. Slope of a Velocity vs Time Graph:

    • The slope of a velocity vs time graph represents the acceleration of the object. A positive slope indicates increasing acceleration, while a negative slope indicates deceleration.

  5. Possible Actions When an Object is Accelerating:

    • An object could be:

      • Speeding up (increasing velocity)

      • Slowing down (decreasing velocity)

      • Changing direction (maintaining speed but altering motion path)

  6. Analyzing the Position vs Time Graph:

    Position vs Time Graph

    • a. Object's Position at t = 25s:

      • Inspect graph at t = 25s for the y-coordinate to determine position.

    • b. Object's Velocity from t = 0s to t = 10s:

      • Calculate the slope between points at t = 0s and t = 10s on the graph.

    • c. Object's Velocity from t = 10s to t = 15s:

      • Determine the change in position over the time interval from t = 10s to t = 15s.

    • d. Object's Velocity from t = 15s to t = 40s:

      • Assess the slope on the graph between t = 15s to t = 40s.

    • e. When is the Object at Rest?:

      • An object is at rest when its position vs time graph is horizontal (slope = 0).

    • f. When is the Object Moving to the Left (Negative Velocity)?:

      • The object moves left (has negative velocity) when the slope of the position vs time graph is negative (descending slope).