# Activities

• • • ##### Subject Area

• Math: Algebra I: Quadratic Functions

• ##### Author 9-12

60 Minutes

• ##### Software

TI InterActive!™

• ##### Other Materials
This is Activity 7 from the EXPLORATIONS Book:
TI InterActive! Math for High School

## Stopping Distances

#### Activity Overview

In this activity, students learn to build a model for the total distance required to stop a moving vehicle.

#### Before the Activity

• See the attached PDF file for detailed instructions for this activity
• Print pages 59 - 63 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to the class.

Follow the Activity procedures:

• Enter speed, perception-reaction distance, braking distance, and total stopping distance data as lists
• Graph speed versus perception-reaction distance
• Determine the type of equation that will model the graphed data
• Enter speed and reaction data and use linear regression function to obtain a regression equation
• Graph the regression equation and find the slope and y-intercept
• Observe that the equation fits the data

• Graph speed versus braking distance data
• Determine the type of equation that will model the graphed data
• Write the mathematical statement of the relationship between braking distance and velocity
• Enter data and use quadratic regression to calculate the regression equation
• Find the values of b and c in the regression equation according to the relationship equation
• Write an equation for the braking distance and observe that the equation fits the graphed data

• Graph total distance (braking distance + reaction distance) versus speed data
• Determine the type of equation that will model the graphed data
• Find the equation for total stopping distance using previous equations of perception-reaction distance and braking distance
• Compare equations and see how well the equation for total distance fits the data
• Use the model to predict the stopping distance of a car traveling at a given speed and also the speed of a car whose stopping distance is a specified value
• #### After the Activity

Students complete the Student Activity sheet.

Review student results:

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