title: "Vehicle Collisions" course: "standard-physics" unitSlug: "unit-1-collisions" topicSlug: "vehicle-collisions" tags:

• "momentum"
• "collision"
• "openscied" storylineStep: 2

Vehicle Collisions

Driving Question

Why do some collisions cause more damage than others?

In this unit, students investigate how force, mass, momentum, and collision time affect outcomes.

Core Idea

Momentum is defined as:

$p = mv$ Momentum equals mass times velocity.

During a collision, total momentum of a closed system is conserved:

$\sum p_{\text{before}} = \sum p_{\text{after}}$ The sum of momentum before a collision equals the sum of momentum after a collision.

Discussion Prompts

• How does increasing stopping time reduce average force during a crash?
• Why do crumple zones improve safety even when they increase visible damage?
• Which variables can drivers control before a collision occurs?