Finding Distance b/w Point A and B with Kinematic Formulas

  • Thread starter lektor
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In summary, the conversation discussed using kinematic formulas to find the distance between two cars that are moving towards each other along a straight road. The formula D = \frac{(v_{01} + v_{02})^2 - (\frac{a_1 + a_2}{2\Delta t})^2}{2(a_1 + a_2)} was proposed, but there was a discrepancy in the units. Another formula, D = \frac{\sqrt{\Delta}}{a}, was suggested and it was explained that this formula can be derived by expressing the positions of the cars in terms of time and solving for D.
  • #1
lektor
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This question is just a practice for creating equations for suiting situations but i feel as if I've taken the completely wrong appoach..


Two cars begin to move toward each other simultaneously along a straight road. Car 1 starts from point A at a speed of V1; Car 2 starts at point B at a speed V2.The acceleration of car 1 is a1; it is directed toward A,
The acceleration of car 2 is a2; it is directed toward B. In the process of motion, the cars meet twice; the time interval between the meetings is t. Find the distance between A and B.

Some help would be great, so far my approach was using kinematic formulas.

I finished with [tex]D = \sqrt{\frac{Vi1*T*a1*T^2}{Vi2*T*a2*T} } [/tex]

Sorry about the mathlatex in currently reading the guide.
 
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  • #2
The units in your result don't agree. They are ms, and not m.

I came up with this formula:


[tex]D = \frac{(v_{01} + v_{02})^2 - (\frac{a_1 + a_2}{2\Delta t})^2}{2(a_1 + a_2)}[/tex]
 
  • #3
ramollari said:
The units in your result don't agree. They are ms, and not m.

I came up with this formula:


[tex]D = \frac{(v_{01} + v_{02})^2 - (\frac{a_1 + a_2}{2\Delta t})^2}{2(a_1 + a_2)}[/tex]

Your Answer looks quite well thought out, could you please give some explanations of how you reached it :)?
 
  • #4
Express the positions x of both vehicles in terms of time. Equalize them, and you get a quadratic equation for time, that of course gives two results. Then, the procedure is simple:

[tex]\Delta t = \frac{\sqrt{\Delta}}{a}[/tex]

Both Delta and a will contain the quantities D, a1, a2, v01, v02. So, solve for D to arrive at that result.
 

Related to Finding Distance b/w Point A and B with Kinematic Formulas

1. What are kinematic formulas?

Kinematic formulas are a set of equations that describe the motion of an object in terms of its position, velocity, and acceleration. They are commonly used in physics and engineering to calculate the distance, speed, and time of an object's motion.

2. How do kinematic formulas help in finding distance between two points?

Kinematic formulas provide a mathematical framework for calculating the distance between two points by taking into account the initial and final positions, velocities, and accelerations of the object. By plugging in these values into the appropriate formula, we can accurately determine the distance traveled by the object.

3. What are the basic kinematic formulas used for finding distance?

The three basic kinematic formulas used for finding distance are:

  • Distance (d) = Initial Velocity (v0) x Time (t) + 1/2 x Acceleration (a) x Time (t)2
  • Distance (d) = (Final Velocity (v) + Initial Velocity (v0)) x 1/2 x Time (t)
  • Distance (d) = Initial Velocity (v0) x Time (t) + 1/2 x Acceleration (a) x Time (t)2

4. What units should be used when using kinematic formulas to find distance?

When using kinematic formulas to find distance, it is important to use consistent units for all variables. Common units include meters (m) for distance, meters per second (m/s) for velocity, and meters per second squared (m/s2) for acceleration. It is important to convert units as needed to ensure accurate calculations.

5. Can kinematic formulas be used for objects with changing acceleration?

Yes, kinematic formulas can be used for objects with changing acceleration, as long as the acceleration is constant at each point in time. However, for objects with non-constant acceleration, more advanced kinematic equations, such as those incorporating calculus, may be needed to accurately determine the distance between two points.

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