Physics
Physics
Problem
A 2 kg ball moving at 4 m/s collides elastically with a 3 kg ball at rest. Find the final velocities.Intuitive explanation
Elastic collisions conserve both momentum and kinetic energy—two constraints that let you solve for two unknowns (the final velocities). The key is to set up both conservation equations and recognize that elastic collisions have a special property: the relative velocity of approach equals the relative velocity of separation. This often makes the algebra cleaner than expanding kinetic energy directly.
Intuitive explanation
Elastic collisions conserve both momentum and kinetic energy—two constraints that let you solve for two unknowns (the final velocities). The key is to set up both conservation equations and recognize that elastic collisions have a special property: the relative velocity of approach equals the relative velocity of separation. This often makes the algebra cleaner than expanding kinetic energy directly.