- #1
jnimagine
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Homework Statement
A car, traveling at a speed of 90km/h, approaches a stop sign 40m ahead. If the car immediately begins to decelerate at a rate of -8m/s^2, will it be able to stop in time? Justify your response
Homework Equations
d = 1/2at^2 + vt
The Attempt at a Solution
I found time by doing t = v/a and found it to be 25/8s
Then I subbed it in d = 1/2at^2 + vt and got an answer of 39.1m, which is smaller than 40m. So it will be able to stop in time.
But this assignment is all about differentiation, so I should be finding a derivative somewhere... but I don't know where to find a derivative to solve this problem!
Please help~~