Consider two cars one a chevy, one a Ford. The Chevy is speeding along

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Discussion Overview

The discussion revolves around the effects of initial velocity on the stopping time and distance of two cars, a Chevy and a Ford, both braking with the same constant acceleration. Participants explore the implications of initial speed on these kinematic aspects without reaching a consensus.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions the clarity of the original question and breaks it down into simpler components regarding the influence of initial velocity on stopping time and distance.
  • Another participant points out a numerical error in the initial speeds provided, noting that 30 is not half of 50.
  • A different participant explains that both stopping distance and time are dependent on initial velocity, referencing kinematic equations to support this view.
  • One participant summarizes the discussion by restating the question about the effects of initial velocity on stopping distance and time, suggesting that the previous explanations were unnecessarily complex.

Areas of Agreement / Disagreement

Participants express differing levels of understanding regarding the original question, and while some agree on the dependence of stopping distance and time on initial velocity, others challenge the clarity and accuracy of the initial statements. No consensus is reached on the overall interpretation of the question.

Contextual Notes

There are unresolved issues regarding the initial speeds mentioned, and the discussion reflects varying interpretations of the question's intent. The mathematical relationships presented depend on the assumption of constant acceleration.

tarheels88
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Consider two cars one a chevy, one a Ford. The Chevy is speeding along at 50m/s (mph) and the Ford is going half the speed at 30m/s. If the two cars brake to a stop with the same constant acceleration, are either the amount of time required to come to a stop, or the distance traveled prior to stopping influenced by their initial velocity.

I don't really understand the concept of what the question is asking. And no this is not a Homework question.
 
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Is it simply trying to parse the poorly worded paragraph? Here it is broken apart.Consider two cars one a chevy, one a Ford. The Chevy is speeding along at 50m/s (mph) and the Ford is going half the speed at 30m/s. The two cars brake to a stop with the same constant acceleration.

Is the amount of time required for each vehicle to come to a stop influenced by its initial velocity? Y/N

Prior to each vehicle stopping is the distance it traveled influenced by its initial velocity? Y/N
 


Not that important, but 30 is not half of 50.
 


It sounds to me like the question is asking you, what things depend on your speed when you undergo constant deceleration? Constant acceleration allows us to use a collection of well-worn kinematical laws, and here are two:
the change in v2 = 2 a s, where s is the distance traveled.
the change in v = a t, where t is the time.
In both cases, if you are interested in stopping, then v is just the initial velocity, and you get
s = v2/2a
t = v/a
and you clearly see that both the stopping distance, and the stopping time, depend on initial velocity v. You can also see the point commonly stressed in driver's education-- the stopping distance is especially sensitive to initial v, so if you speed, you will have a hard time stopping before you hit an object a fixed distance in front of you.
 


Are the stopping distance and/or stopping time affected by a car's initial velocity?

Kind of a long, confusing, mathematically unnecessary and inaccurate way of saying the above.
 

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