Kinematics Car acceleration Problem

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Homework Help Overview

The problem involves two cars, a red car moving with constant velocity and a green car with constant acceleration, approaching each other on a straight path. The red car's positions at different velocities are given, and the task is to determine the initial velocity and acceleration of the green car.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the need to find the time until the cars pass each other and how to isolate the green car's motion. Some suggest using specific equations of motion to relate the distances traveled by both cars.

Discussion Status

There is an ongoing exploration of how to approach the problem, with some participants offering guidance on using equations of motion. Multiple interpretations of the problem setup are being considered, and participants are encouraged to make their own attempts.

Contextual Notes

Some participants mention that they have not yet covered this topic in class, indicating a potential gap in foundational knowledge. There are references to guidelines for participation and expectations for effort in problem-solving.

hiineko
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Homework Statement


In the figure here, a red car and a green car move toward each other in adjacent lanes and parallel to an x axis. At time t = 0, the red car is at xr = 0 and the green car is at xg = 223 m. If the red car has a constant velocity of 20.0 km/h, the cars pass each other at x = 43.1 m. On the other hand, if the red car has a constant velocity of 40.0 km/h, they pass each other atx = 76.9 m. What are (a) the initial velocity and (b) the (constant) acceleration of the green car? Include the signs.

Homework Equations


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hiineko said:
In the figure here, a red car and a green car move toward each other in adjacent lanes and parallel to an x axis. At time t = 0, the red car is at xr = 0 and the green car is at xg = 223 m. If the red car has a constant velocity of 20.0 km/h, the cars pass each other at x = 43.1 m. On the other hand, if the red car has a constant velocity of 40.0 km/h, they pass each other atx = 76.9 m. What are (a) the initial velocity and (b) the (constant) acceleration of the green car? Include the signs.
So you have one car moving with uniform velocity , and the other with constant acceleration .

What have you tried until now ?
 
Can you find the time until passing in each case?
Then you've gleaned all the info required from the red car and can focus on the green only..
 
Qwertywerty said:
So you have one car moving with uniform velocity , and the other with constant acceleration .

What have you tried until now ?

At the moment sir we haven't tackled this lesson but the prof gave us this problem for advance studying so I'm just posting it here in physics forum in helping tackled this problem atm I thinking if I can use the 3rd formula then I'll plug values to get equation 1? Just my 2 cents
 
hiineko said:
At the moment sir we haven't tackled this lesson but the prof gave us this problem for advance studying so I'm just posting it here in physics forum in helping tackled this problem atm I thinking if I can use the 3rd formula then I'll plug values to get equation 1? Just my 2 cents
Consider the initial velocity of the green car as u , and it's acceleration as a .

So you have two unknowns . Do you know the distance that the car travels in the first and second case ? Use equation 3 .

Hope this helps .
 
Qwertywerty said:
Consider the initial velocity of the green car as u , and it's acceleration as a .

So you have two unknowns . Do you know the distance that the car travels in the first and second case ? Use equation 3 .

Hope this helps .
Will update you sir if I can find any shed of light in this problem thankyou!
 

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