Full Stop Ahead
To reduce the likelihood of an accident when driving, you should consider how far your car will travel before safely coming to a stop for the speed at which you are traveling. Assume you are traveling on a dry road and have an average reaction time. The formula d = 0.044s2 + 1.1s gives you a safe stopping distance d in feet, where s is your speed in mi/h. Make a table of values for speeds of 10, 20, 30, 40, 50, and 60 mi/h. Then, graph the function.
Suppose a car left a skid mark d feet long. The formulas will estimate the speed s in miles per hour at which the car was traveling w1hen the brakes were applied.
Why do you think the estimates of speed do not double when the skid marks double in length? Based on these results, what conclusions can you make about safe distances between cars?
I don't think they doubled because there's enough traction on the tires to stop the car and the brakes work good so it doesn't slide.
Suppose you are driving on a dry road with 150 ft (about 10 car lengths) between your car and the car in front of you. Use the formula from Activity 1 to find the maximum speed you should be traveling in order to leave a safe stopping distance.
The maximum speed you could go without running into the car in front of you is 47. Because if you go any faster you'll get to close to the car in front of you.