<PRE><B>Question 98881</B>
At the instant the traffic light turns green, an automobile starts with a constant acceleration of a 2.5m/s^2. At the same instant a truck traveling with a constant speed of 7.1 m/s, overtakes the automobile.
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THis looks like a physics problem, but this is what I think.
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When the car overtakes the truck, they will have traveled the same distance.
Since the car was stopped, it will have to accelerate to twice the speed (which
is 14.2 m/s), of the truck to average the same speed as the truck to that point:
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Time to accelerate to 14.2 = {{{14.2/2.5}}} = 5.68 sec
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(A) how far beyond the traffic signal will the automobile overtake the truck?
5.68 * 7.1 = 40.328 meters
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(B) how fast will the car be traveling at that instant
14.2 m/s will be the speed of the car.
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