A roadside safety barrier is being designed to stop a passenger car traveling at…
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Linear Momentum · Linear Momentum
Problem
A roadside safety barrier is being designed to stop a 1.5×103kg passenger car traveling at 12ms−1 straight into it. Engineers want to limit the magnitude of the average horizontal force exerted on the car to no more than 7.5×104N so that occupants experience survivable accelerations. Assume the car comes to rest without rebounding and that the horizontal deceleration is approximately constant.
(a) Determine the magnitude of the change in momentum of the car during the collision.
(b) Using the force limit, calculate the minimum time the collision must last.
(c) Under the constant-deceleration assumption, compute the minimum stopping distance that the barrier must provide.
(d) Discuss two practical factors that could cause the actual stopping distance of a real collision to differ from your value in part (c).