Physics
Physics
Problem
Two automobiles collide head-on on a straight, level road that defines the x-axis. • Car X: mass , traveling east at • Car Y: mass , traveling west at After impact the wreckage locks together and skids as a single unit. Assume the road is horizontal and external horizontal forces during the very short collision are negligible. (a) Taking east as the +x-direction, calculate the total linear momentum of the system just before impact. Express your answer with the proper sign and units. (b) Determine the velocity (magnitude and algebraic sign) of the combined wreckage immediately after the collision. (c) Describe in words what the sign of your answer in part (b) indicates about the motion of the wreckage relative to both cars’ original directions.Intuitive explanation
This is a perfectly inelastic collision where momentum is conserved even though kinetic energy is lost. The key is to set up a consistent sign convention (east positive, west negative), add the momenta before and after impact, and solve for the final velocity of the locked wreckage. Since the collision time is extremely short, friction during impact is negligible—only the internal collision forces matter.
Intuitive explanation
This is a perfectly inelastic collision where momentum is conserved even though kinetic energy is lost. The key is to set up a consistent sign convention (east positive, west negative), add the momenta before and after impact, and solve for the final velocity of the locked wreckage. Since the collision time is extremely short, friction during impact is negligible—only the internal collision forces matter.