Thursday, September 15, 2011

How much time does it take for the Porsche to catch the Honda?

Two cars, a Porsche and a Honda, are traveling in the same direction, although the Porsche is 184 m behind the Honda. The speed of the Porsche is 23.9 m/s and the speed of the Honda is 17.9 m/s. How much time does it take for the Porsche to catch the Honda? [Hint: What must be true about the displacements of the two cars when they meet?]|||Hey!





Here's the entire answer to your question.





Let's first identify the values we're given:





d = distance Porsche is behind Honda = 184 m





V = speed of Porsche = 23.9 m/s





v = speed of Honda = 17.9 m/s





The "hint" in the problem asks what must be true about the displacements of the cars when they meet? Well, the displacements must be EQUAL if they meet:





displacement of Honda = displacement of Porsche





or





d(Honda) = d(Porsche)





Now let's figure out what these displacements are. Assume that the INITIAL position of the Porsche is d = 0. Then:





d(Honda) = d + v*t





d(Porsche) = V*t





Now we equate these two values:





d + v*t = V*t





Here t = time, which is what we're solving for. Rearranging terms to solve for t:





t = d / (V-v)





= 184 m / (23.9 m/s - 17.9 m/s)





= 30.66 seconds








So the Porsche will catch up to the Honda in 30.66 seconds. That's your answer!























anaGah.|||The basic formula would be vp * t = vh * t + x


Rewrite as t = x / (vp - vh) = 184 / (23.9 - 17.9) = 184 / 6 = 30.6 seconds.|||Tiempo de alcance:





Ta = d / ( V1 - V2).....................( V1 %26gt; V2 )





Ta = 184 / (23,9 - 17,9) = 30,67s





Suerte!!! consultas: mir_urss@hotmail.com

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