PASCO
MAIN PROCEDURE
   
In this experiment, students analyze the relationship between the change in momentum and impulse for a stomp rocket.
 
  • Plastic Soda Bottle 2 Liter
  • Duck Tape
  • 1/2 inch PVC tube 32 cm long
  • 1/2 inch PVC tube 20 cm long
  • 1/2 inch PVC elbow
  • Four 1-1/4 inch #6 wood screws
  • Conduit Strap
  • 5-minute Epoxy Glue
  • Packing Material or Foam
  • Wood Block 3.5" x 3/5" x 1.5"
  • 36 cm x 60 cm Masonite
Safety:

Do not alter the rocket!
Do not point the rocket at anyone!
  1. Record the mass of the rocket.

  2. Load the rocket and aim it in a safe direction.

  3. Press the START button in DataStudio.

  4. Firmly stomp downward on the plastic bottle.

  5. Press the STOP button in DataStudio.

  6. Record the maximum velocity of the rocket.
    DataStudio
  1. Using the cursor, highlight the section of the Force-Time graph that corresponds to the launching of the rocket.

  2. Observe the statistics window in the Force-Time graph. It automatically calculates the area of the Force-Time graph that was highlighted. Record the area of the Force-Time graph.

  3. Calculate the rocket's change in momentum.

  4. Repeat the Data Collection Procedure steps and the Analysis steps for a rocket with two pennies taped to it and with 4 pennies taped to it.
 

Area of Force-Time
Units: (          )

Change in Momentum
Units: (          )

Rocket
only

    

Rocket with
2 pennies

   

Rocket with
4 pennies

   
  1. Notice that the DataStudio screen collects raw Absolute Pressure data over time. Equation(s) were written to convert the Absolute Pressure data to Force data. What is/are the equation(s)?

  2. Enter the units for the Area of the Force-Time graph and the units for the Change in Momentum into the table above.

  3. What is the physical meaning of the area of the Force-Time graph?

  4. According to your results, state the relationship between the change in momentum of the rocket and the area of the Force-Time graph.

  5. Draw qualitative force diagrams for each launch.

  6. In what direction is the net force and acceleration during the launch of the rocket? Explain.

  7. A constant force of F is applied over a time t to launch a rocket. How would the change in momentum be affected if the force is decreased by 1/2 F and the time to launch is increased to 2t.