What is the g-force of a car stopping on a dime?

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Discussion Overview

The discussion revolves around calculating the g-force experienced by a car that comes to a stop over the diameter of a dime, with an initial speed of 55 mph. Participants explore various methods to derive the acceleration and subsequently the g-force, involving concepts of kinematics and unit conversions.

Discussion Character

  • Technical explanation, Mathematical reasoning, Debate/contested

Main Points Raised

  • One participant asks for the g-force when a car stops from 55 mph across a dime's diameter.
  • Another suggests converting mph to meters per second, finding acceleration from the change in velocity, and then calculating the g-force.
  • A different participant proposes using a system of equations to relate distance, acceleration, and time, suggesting a specific calculation that results in approximately 1721g.
  • Another participant provides a formula for acceleration based on initial and final velocities, noting that this assumes constant acceleration.

Areas of Agreement / Disagreement

Participants express differing methods for calculating the g-force, and no consensus is reached on the correct approach or final value.

Contextual Notes

Assumptions about constant acceleration and the specific distance used in calculations are not universally agreed upon. The discussion also involves different interpretations of initial conditions and reference frames.

Loren Booda
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What is the g-force on a car, initially traveling at 55 mph, when stopping across the diameter of a dime?
 
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convert mph to mps, find the acceleration from change in velocity, multiply by mass, divide by g.
 
Find acceleration from change in velocity over given distance, that is.
 
Would it not be appropriate to solve a system of equations, d=1/2 * a * t^2, d = 17.91 mm, and a * t = 55 mph?

Doing this I get about 16.9 kilometers / s^2, or 1721g.
 
Last edited:
[tex]a = \frac{v^2 - v_0^2}{2d}[/tex]

but [tex]v_0 = 0[/tex] (in my ref frame : )

so

[tex]a = \frac{v^2}{2d}[/tex]

Of course, this assume constant acceleration...
 

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