Can a Car Turn 90 Degrees at High Speeds Using a Grappling Hook?

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Discussion Overview

The discussion revolves around the feasibility of a car making a 90-degree turn at high speeds using a grappling hook, as depicted in a scenario inspired by a Mythbusters episode. Participants explore the physics involved, particularly centripetal forces, and the potential consequences of such a maneuver on both the vehicle and its occupants.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions how to create a force diagram for an object experiencing centripetal forces, indicating a lack of prior knowledge on the topic.
  • Another participant challenges the initial force diagram, suggesting that the direction of the engine's force and friction changes as the car turns, and that the force due to momentum change must be considered.
  • A concern is raised regarding the survivability of a human in the car due to the high acceleration experienced during the turn, with references to potential fatal injuries.
  • Mathematical calculations are presented to illustrate the extreme acceleration a car would experience at high speeds with a very tight turn radius, suggesting that survival is unlikely.
  • A humorous remark is made about the survival of the signpost in the scenario, implying the extreme forces involved.
  • One participant expresses curiosity about the creation of diagrams shared in the discussion, indicating a desire to learn more about the graphical representation of physics concepts.
  • The tension in the grappling hook cable is discussed, with estimates provided for the forces involved and the implications for the cable's material strength.
  • Additional information about potential injuries related to rapid acceleration and deceleration is offered, suggesting that further research could be beneficial for understanding the biomechanics involved.

Areas of Agreement / Disagreement

Participants express various viewpoints on the physics of the scenario, with no consensus reached on the feasibility of the maneuver or the implications for safety. Multiple competing views remain regarding the forces involved and the potential outcomes of such a high-speed turn.

Contextual Notes

Limitations include assumptions about the car's speed, turn radius, and the physical properties of materials involved in the scenario. The discussion does not resolve the complexities of the forces at play or the safety implications of the proposed action.

Who May Find This Useful

This discussion may be of interest to students learning about centripetal forces, physics enthusiasts curious about practical applications of physics concepts, and individuals interested in biomechanics and safety in high-speed scenarios.

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I'm just a high school physics student, and this is my first physics class. Anyways, I was watching Mythbusters a few days ago and saw the myth that a car could turn 90 degrees @ high speeds if a grappling hook was shot out at a structure at the corner of a turn (see diagram below). I've never dealt with centripetal forces before and was just wondering how you would create a force diagram for an object with centripetal forces.
http://img111.imageshack.us/img111/4167/carscenarioks7.jpg
Here's my take on it, but I'm just blindly guessing here:
http://img405.imageshack.us/img405/7481/cardiagrasmk3.jpg
Note that the car is already caught in the circular motion when position 2 is drawn. Also, forgive my messy handwriting and drawings :)
 
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well i think you got the fpr and f on the car by engine wrong cause when the car is turned the engine of the car gives the force along the direction where the car is pointing (provided the wheels of the cars are not turned) and also the friction on th motion ofthe car depends on the direction the car is moving so since the car is is turning the direction of friction force also changes... also i would like to point out that the f nx will be caused because of the change of momentum of tha car as it turns... hope this helps :shy:
 
XTTX,
Besides the the centripetal force question, there is the very great possibility that a human in that car will not survive the fairly high da/dt at the tangent point of the curve. Likely, cervical injury or "brain spin" would be fatal, depending on the speed and radius of curvature.
 
Using the equation :

a = (v^2)/r

Lets say the car is traveling at 70 mph and the radius of the turn is 2m.

a = (31.11^2)/2 = 484 m/s^2

Or 50g, so yea its unlikely you would survive that lol
 
Less likely that the signpost will survive.
 
XTTX said:
I'm just a high school physics student, and this is my first physics class. Anyways, I was watching Mythbusters a few days ago and saw the myth that a car could turn 90 degrees @ high speeds if a grappling hook was shot out at a structure at the corner of a turn (see diagram below). I've never dealt with centripetal forces before and was just wondering how you would create a force diagram for an object with centripetal forces.
http://img111.imageshack.us/img111/4167/carscenarioks7.jpg
Here's my take on it, but I'm just blindly guessing here:
http://img405.imageshack.us/img405/7481/cardiagrasmk3.jpg
Note that the car is already caught in the circular motion when position 2 is drawn. Also, forgive my messy handwriting and drawings :)
how did you make those images
 
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The tension in the cable is going to be pretty high though, say you had a fairly normal 1.5 ton saloon (think that's probably about right), that's a tension of something like 726kN so if your cable is made out of something like mild steel it'll need to be fairly thick to deal with it and firing a cable like that at the extremely strong signpost in the first place is going to be pretty difficult.
 
I did not give sufficient information about da/dt injury. If the reader wants, there is a wealth of information to be found in most biomechanics texts, or by Googling Contrecoup injury or whiplash.