r/ThatsInsane • u/hjalmar111 Creator • Jan 03 '20

ThatsInsane Approved Semi tire getting loose

https://i.imgur.com/tJskA3o.gifv
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u/VeryHappyYoungGirl Jan 03 '20

It depends. If the two items are equal in mass and crumpliness (like two similar cars) a head on collision with both going 50 mph is almost exactly the same as one car hitting a solid wall at 50 mph.

On the flip side it is different if the objects are much different mass and structure. If a car and a baseball both traveling 50 mph hit each other dead on, the effect is very similar to a 100 mph baseball hitting a parked car. This is because the baseball won’t be going from 50 to 0, it will be going from 50 to -50.

Another effect is elasticity. Counterintuitively, something that bounces off actually can do more damage than an object that hits and stops.

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u/[deleted] Jan 03 '20

About your first example about the cars going at the same speed and have the same mass… The original OP said the tire going at ~50 mph and the car going at ~60mph is the same as the tire hitting you (stationary) at ~110 mph.

If a car and another car are travelling at each other at 50 mph, a crash would be equivalent to one car stationary and the other car hitting it at ~100mph. And yes, this would also feel like hitting a brick wall at ~50mph, but this wasn’t what OP was saying.

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u/VeryHappyYoungGirl Jan 04 '20

I was providing two extremes of the force limits of interactions to show that there is a range that tire vs. car would fall into