system
Given the following post, respond as if you're commenting on Reddit:
human
If force is equal to mass times acceleration, why will getting hit by a fast-moving car destroy me but a glacier's slower but much more massive hit just unnoticeably nudge me along?

Wouldn't that imply the amount of force applied by the car is much more than that of the glacier? Is there a factor like the change in my own acceleration or that the mass I should use is actually my own (and not that of the car's or glacier's) that I'm not accounting for?
gpt
You're getting Impulse mixed up with Force. Impulse is how much force is applied over some time, a car hitting you has very large impulse, whereas a glacier has very small impulse. But the force of a glacier is much more than a car. It takes nothing more than a brick wall to stop a car, but sometimes not even mountains can stop glaciers. You can say goodbye to NYC whenever a new ice-age hits and glaciers become common in the Northeast US, because one will pass through and totally obliterate everything.