Asked by Anonymous

Using the equation for Impulse, can you explain the following:
Why are car steering rods designed to collapse?
Why are highway guard rails designed to crumple up on impact?
Answered by Damon

Force = rate of change of momentum
force * time = change of momentum = impulse
if we have mass m moving at speed v, momentum m v and have to stop it with minimal force, we do it over a longer time.