Read E-49

Activity 84

Title: Decelerating Safely

Problem: How can a person’s deceleration be controlled during a collision?

Hypothesis: If _____, then __________.

How do you know when you are accelerating while traveling in a car?• Starting up from a stoplight.

• Passing a vehicle.

• Acceleration is happening when you have the feeling of being pushed back in the seat while the car accelerates forward.

How do you know when you are decelerating while traveling in a car?

• When a car comes to a stop, it will make passengers feel like they are thrown forward as the car decelerates.

Talking Drawing: Safety Features

• Close your eyes and think about what a safe vehicle looks like. Now, open your eyes and draw what you imagined. Label any parts of the vehicle that have special features.

Three Level Reading Guide

• Check the statements that are correct in the first two sections.

• In the third section, check the statements that you believe are correct.

Talking Drawing: Part II

• Redraw your safe car with added safety features that you read about.

Analysis Question #1

• What did you pick?• On impact, the car decelerates very rapidly,

but inertia keeps objects within the car, including people, moving at a higher speed.

• How does your chosen safety feature help decelerate the body more gradually, so that there is an increase in time and a reduction in force?

Analysis Question #3

• Tires are designed to optimize the friction between them and the road so that the car gets good traction, handles well, and can stop quickly.

• As tires wear down, their ability to do all these safety-related things decreases and the braking distance increases.

Analysis Question #4

• Some of the factors that tend to keep the fatality rate about the same are:– More distractions, such as cell phones and

hand-held electronic devices– A larger number of older drivers– Lack of seatbelt use (almost 40% of all

passengers killed are not wearing seatbelts)– Reintroduction of higher speed limits– Less car uniformity (mass, bumper height) when

vehicles collide