- #1
lauriecherie
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Homework Statement
On a dry road, a car with good tires may be able to brake with a constant deceleration of 4.06 m/s2.
(a) How long does such a car, initially traveling at 23.6 m/s, take to stop?
5.813 s This answer is correct.
(b) How far does it travel in this time?
I've tried 59.47 m and 137.1868 but Webassign says both are incorrect. I have no clue as to what I am doing wrong.
Homework Equations
x(t)= initial position + final velocity * time
v(t)= (acceleration * time) + initial velocity
x(t)= .5 * (acceleration * (time^2)) + (initial velocity * time) + inital position
x= initial position * (average velocity * time)
average velocity= (final velocity - initial velocity) / (2)
(final velocity^2) - (initial velocity^2) = 2 * acceleration * change in position
The Attempt at a Solution
I got 59.47 meters by pluging in part a, 5.813 seconds, into the position function.
Then I tried 137.19 meters after figuring that in 5.813 seconds at 23.6 m/s (I multiplied the two) it could travel 137.19.
Any ideas on what I am doing wrong?