Velocity Unit Test


Honors Physics Quiz

Physics Quiz
Goal:  You must have ten (10) successful
trials (SCORE) using different objects/variables.

There is a chart to support the lab

Virtual Lab starts Here

Questions for Journaling:

  1. Did you observe a difference with and without air resistance in your experiment (for example compare a golf ball to another golf ball or one object to a different object both with air resistance or without)?  Explain what you observed in the data.
  2. What is range of the target (where did you find success)?
  3. The drag coefficient consistently changes. What do you think causes this inconsistency?  Provide specific examples of this change?





Velocity Key Ideas

A distance-time graph tells us how far an object has moved with time.
  • The steeper the graph, the faster the motion.
  • A horizontal line means the object is not changing its position - it is not moving, it is at rest. 
  • A downward sloping line means the object is returning to the start.

Position-Time
(Displacement vs. Distance)
Distance and displacement are two quantities that may seem to mean the same thing yet have distinctly different definitions and meanings.
  • Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion.
  • Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.
To test your understanding of this distinction, consider the motion depicted in the diagram below. A physics teacher walks 4 meters East, 2 meters South, 4 meters West, and finally 2 meters North.

Example:                        
Picture
Even though the physics teacher has walked a total distance of 12 meters, her displacement is 0 meters. During the course of her motion, she has "covered 12 meters of ground" (distance = 12 m). Yet when she is finished walking, she is not "out of place" - i.e., there is no displacement for her motion (displacement = 0 m). Displacement, being a vector quantity, must give attention to direction. The 4 meters east cancels the 4 meters west; and the 2 meters south cancels the 2 meters north. Vector quantities such as displacement are direction aware. Scalar quantities such as distance are ignorant of direction. In determining the overall distance traveled by the physics teachers, the various directions of motion can be ignored.
Speed and Velocity
Just as distance and displacement have distinctly different meanings (despite their similarities), so do speed and velocity. Speed is a scalar quantity that refers to "how fast an object is moving." Speed can be thought of as the rate at which an object covers distance. A fast-moving object has a high speed and covers a relatively large distance in a short amount of time. Contrast this to a slow-moving object that has a low speed; it covers a relatively small amount of distance in the same amount of time. An object with no movement at all has a zero speed.
Velocity is a vector quantity that refers to "the rate at which an object changes its position." Imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. While this might result in a frenzy of activity, it would result in a zero velocity. Because the person always returns to the original position, the motion would never result in a change in position. Since velocity is defined as the rate at which the position changes, this motion results in zero velocity. If a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. Every step must go into moving that person further from where he or she started. For certain, the person should never change directions and begin to return to the starting position.

​Velocity is a vector quantity. As such, velocity is direction aware. When evaluating the velocity of an object, one must keep track of direction. It would not be enough to say that an object has a velocity of 55 mi/hr. One must include direction information in order to fully describe the velocity of the object. For instance, you must describe an object's velocity as being 55 mi/hr, east. This is one of the essential differences between speed and velocity. Speed is a scalar quantity and does not keep track of direction; velocity is a vector quantity and is direction aware.
​
In conclusion, speed and velocity are kinematic quantities that have distinctly different definitions. Speed, being a scalar quantity, is the rate at which an object covers distance. The average speed is the distance (a scalar quantity) per time ratio. Speed is ignorant of direction. On the other hand, velocity is a vector quantity; it is direction-aware. Velocity is the rate at which the position changes. The average velocity is the displacement or position change (a vector quantity) per time ratio.

Physics Help:

Displacement vs. Distance

Velocity


Velocity Research

Create a table in your journal and complete the following Velocity topics in your journal - please be thorough in your explanation:

1.  What is terminal velocity (free fall)?
2.  What is the escape velocity on Earth (explain)? 
      Is this the same on all planets?
3.  Create a table for the following values:
    - Speed of the fastest human (skiing, swimming,
      walking, running, cycling)
    - Speed of the fastest vehicles (production car,
      airplane, experimental vehicle-ground,
      experimental vehicle-air, water craft, military
      vehicles)
    - Speed of the fastest animals (select the top five fastest animals) 
Velocity Virtual Labs
Complete the racing car virtual laboratory in your journal on the Teacher's Page (Create a table for your trials - you can find a example of the table on the online lab). 
Complete at least five trials with the cars (five races); demonstrate your understanding by calculating and answering the Challenge question. 
Answer all Journal questions from the online lab journal in your personal Physics journal.
Racing Car Virtual Lab