Acceleration, distance, time. help.

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Homework Help Overview

The discussion revolves around a problem involving two vehicles: one traveling at a constant speed and the other accelerating from rest. The objective is to determine the distance traveled by the accelerating vehicle while it catches up to the first vehicle.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants explore the relationship between the positions of the two vehicles over time, suggesting the use of equations of motion for both constant velocity and constant acceleration. There are questions about the initial conditions, such as whether the second vehicle starts from rest.

Discussion Status

Some participants have proposed equations to relate the distances traveled by both vehicles and have attempted to set up a system to solve for the time at which the second vehicle catches up. There is ongoing exploration of the problem, with participants sharing different interpretations and calculations.

Contextual Notes

There are indications of confusion regarding the calculations, with participants questioning specific distance values obtained in their attempts. The problem's complexity is acknowledged, particularly in the context of the vehicles' differing speeds and acceleration profiles.

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Homework Statement



vehicle 1 is traveling at a constant speed of 90mph (132 f/s) 5 seconds before vehicle 2 begins to accelerate from 0-90 mph taking 17.09 seconds to do so. how far a distance will vehicle 2 travel while accelerating to 90mph. and how long will it take for vehicle 2 to catch up to vehicle 1 while accelerating at approximately 5.2 m/s/s or 15.6 f/s

Homework Equations



The relationship between the 2 vehicles is dependent.

what is the total distance traveled by vehicle 2 before it catches up to vehicle 1?


The Attempt at a Solution



ok, it's too hard to explain and argue at the same time, so i'll leave it at this:
find a function of position for car #1 and car #2, call them c_1(t) and c_2(t), set them equal and solve for t. what does this mean exactly?
This should help you a bit, at constant acceleration, call it a, the position of car 2 at time t is at^2/2
the first car, meanwhile is moving at a constant velocity v, so its position at time t is vt
does car 2 start from rest?
so solve vt=at^2/2 -> at^2-vt=0 -> use quadratic formula
this will give you the time t, when car 2 catches up to car 1, ?? to answer part 2 of the Q
 
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For your first question you could use the equation Vf^2 = Vi^2 + 2(a)(d) where Vf is the final velocity, Vi is the initial velocity, a is the acceleration, and d is the displacement.

For number 2, since the first car is traveling at constant speed we can label the distance it travels as d = V(t + 5) while we may use the equation df = (a)(t^2)/2 + (Vi)t + di. Equate the two and solve for the time.
 
did you get a distance of 4044.8 ft for the first part of the question?

or 558.46 ft?
 
Last edited:
anyone get an answer for this?
 

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