Education Technology

Curve Ball

Published on 10/17/2008

Activity Overview

In this activity, students collect data for a bouncing ball using a motion detector. They analyze the data and attempt to find a model for the height of the ball as a function of time.

Before the Activity

  • Connect the computer to the CBL 2™ using the TI connectivity cable

  • Connect CBR 2™ to the CH1 port of the CBL 2™ unit

  • Open a new TI InterActive!™ document
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 69 - 74 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to the class.

    Follow the Activity procedures:

  • Hold the motion detector 5 or 6 feet above the ground
  • Release the ball directly under the detector
  • Collect distance versus time data and plot a graph
  • Convert distance readings to height values
  • Select the data of one bounce
  • Observe the graph is in the form of a parabola
  • Estimate and record the x- and y- coordinates of the vertex
  • Note the theoretical model for an object in free fall is quadratic, and is modeled by the equation y = a(x - h)2 + k
  • Enter coordinates of the vertex (h, k) and find and record the value y
  • Use the model equation and adjust the value of a to find the best fit for the data and record the values of a, h, k, and y
  • Use the TI-InterActive software to find a quadratic curve of best fit
  • Find the regression equation y = ax2 + bx + c and its variables
  • Compare the model equation with the new regression equation and observe that the models are identical
  • After the Activity

    Students complete the analysis and answer questions.

    Review student results:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary