Problem with acceleration and distance

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SUMMARY

The discussion focuses on a physics problem involving two cars: one traveling at speed v and another stationary car that begins to accelerate at a rate of a2. To avoid a collision, the moving car applies brakes, resulting in an acceleration of -a1. The objective is to determine the distance d between the two cars when they just barely avoid colliding, using the variables v, a1, and a2. The solution involves analyzing the position and velocity of both cars over time.

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  • Understanding of kinematics and motion equations
  • Familiarity with acceleration and deceleration concepts
  • Knowledge of velocity-time graphs
  • Basic grasp of Newton's second law (f=ma)
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Homework Statement


v, a1, a2 are the needed variables

A car is traveling in the +x direction with a speed of v when the driver notices a car that is stopped in front of him at distance d. In order to avoid a collision, he immediately applies the brakes resulting in an acceleration of -a1. At the same time, the parked car starts to accelerate in the +x direction with an acceleration of a2. Determine the distance d in terms of v, a1 and a2 if the cars are to just barely avoid a collision.
The only hint I have is: think about the position and velocity of each car. What is required to just barely avoid a collision.




Homework Equations


f=ma


The Attempt at a Solution

 
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efoster said:

Homework Statement


v, a1, a2 are the needed variables

A car is traveling in the +x direction with a speed of v when the driver notices a car that is stopped in front of him at distance d. In order to avoid a collision, he immediately applies the brakes resulting in an acceleration of -a1. At the same time, the parked car starts to accelerate in the +x direction with an acceleration of a2. Determine the distance d in terms of v, a1 and a2 if the cars are to just barely avoid a collision.
The only hint I have is: think about the position and velocity of each car. What is required to just barely avoid a collision.




Homework Equations


f=ma


The Attempt at a Solution


The hint is telling you provided the cars are traveling at the same speed the two cars could contact each other.

I would start by drawing velocity time graphs for the two cars - well actually the front of the traveling car and the rear of the stopped car
 

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