2 ms·
Yeah, but landing on the round hood of a VW Polo vs being hit by the equivalent of a rolling brick wall makes a difference. If you look at the formula for acce
by atoav 4y ago
Yeah, but landing on the round hood of a VW Polo vs being hit by the equivalent of a rolling brick wall makes a difference.
If you look at the formula for acceleration (a = ∆v/∆t) and acceleration force (F = a⋅m) the only two things we can truly influence here are speed (slower collisions are less dangerous) and time (collisions where the force transfer takes longer produce less force).
The latter is what makes the difference between getting hit with an cushion and an equally heavy rock. The same difference exists if you run against a brick wall and against an angled grassy hill (or: a bendy car hood). Not only will the elastic hood (and the roll) absorb part of the collision energy, the angle of the hood stretches the acceleration over longer time and reduces the force transfered on your body.
So if you get the choice as a cyclist, the choice is pretty clear.
- Ygg2 4y agoMass also affects force transferred, during contact. Newton's 3rd law, implies the more mass you have the less recoil you feel. For example hitting a massive box will hurt a lot more than a light box, because light box will get some acceleration of its own vs massive box.
- atoav 4y agoI neglected mass here, because I don't think it really makes much of a difference in the deadliness of the collision (car is always much heavier than cyclist). One thing it would definitely affect tho is the time within which the car could brake, provided they react in time.
- Xylakant 4y agoThough at the mass ratios of car vs pedestrian/cyclists, the difference on the car side makes no significant effect. It doesn‘t really matter if the ratio is 1:10 in favor of the car or 1:20. The acceleration that the car will feel is negligible either way.