Physics Simulation

Projectiles 2 - Time of Fall

[Lab Index]

BHS -> Staff -> Mr. Stanbrough -> AP Physics -> Kinematics -> this page

The vertical component of the motion of a projectile is free fall. This means, for instance, that if you roll a marble off the edge of a level desk, the time that it will take to hit the floor depends only on the height of the desk - not on its initial speed. This can be difficult for beginning physicists to digest, so here is a simulation that may help. In this simulation, you will launch 5 projectiles horizontally from the same position at the same time - all with different horizontal velocities, and observe their fall.

The Simulation:

  1. Sample WorkspaceOpen the Interactive Physics program.
  2. Go to the Workspace submenu of the View Menu and select "Grid Lines".
  3. Go to the Tracking submenu of the World Menu and select "Every 16 frames".
  4. Create 5 new circle objects (Circle tool icon).
  5. Select all 5 new objects, and:
    1. select "Do Not Collide" from the Object Menu.
    2. Open the Properties Window and set:
      1. x = 0.0 m
      2. y = 0.0 m
    3. Open the Appearance Window and check the "Track Connect" box.
  6. Open the Properties Menu and give each mass the horizontal velocity shown in the table (Mass[1]'s velocity stays 0.0):

    Mass #


    (in m/s)

  7. Add your name (Text tool icon) to the simulation.
  8. You can add a "floor" to the simulation using a rectangle (Rectangle tool icon) if you wish, but be sure to anchor (Anchor tool icon) it!

Run the Simulation:

Sample RunRun the simulation, stopping and starting it several times to observe the vertical positions of all of the balls. You can, of course, adjust the starting velocities of balls, and adjust the distance to the "floor". Make a printout, and write a short paragraph explaining the relationship between the distance each ball falls in the same time.

[Lab Index]

BHS -> Staff -> Mr. Stanbrough -> AP Physics -> Kinematics -> this page
last update June 18, 2000 by JL Stanbrough