Comment on xkcd #3084: Unstoppable Force and Immovable Object
dryfter@lemm.ee 1 week ago
I’m driving. I lose my brakes and can’t slow down as if my gas pedal is stuck (unstoppable force). I’m on a road that stops at a T intersection and there’s a concrete wall to keep people from going straight when they are moving vertically towards the T intersection (immovable object).
The car just goes right through the concrete wall with no damage?
Replace the concrete wall with a wooden fence. Technically the fence is immovable, but the car is going to smash right through that thing.
So is this about clarifying what exactly the objects are? I’m not smart enough for this one and am so confused…
The thrust of your car engine is a very stoppable force.
Concrete walls are resilient, but can be moved.
What will happen is that the kinetic energy from the collision will crumple the front part of your car, as the concrete wall applies an equal and opposite force. Ideally, the fact that some of the energy is “used” in deforming your car (and subsequently escapes as heat) decreases the amount of kinetic energy that is used to deform you.
The car just goes right through the concrete wall
Well, maybe…
with no damage?
No.
floquant@lemmy.dbzer0.com 1 week ago
In this example your car is not an unstoppable force, it is just a “travelling” mass
Mostly_Gristle@lemmy.world 1 week ago
The fact that the car had brakes to begin with would suggest that it is, by design, a force which stops regularly.