14.5 : 衝撃

Impact occurs when two bodies collide, resulting in impulsive forces being exerted between them.

To analyze impact mechanics, consider two colliding particles moving along a line passing through their centers, called the line of impact, perpendicular to the contact plane.

When two particles with different initial velocities collide, they cause deformation by exerting equal and opposite impulses.

At maximum deformation, the particles move together with the same velocity.

Following this, restitution occurs, and the particles either return to their original shape or remain permanently deformed.

The equal but opposite restitution impulse pushes the particles apart. Practically, the deformation impulse is always greater than the restitution impulse.

Immediately after the separation, the particle with the lower initial velocity attains a higher velocity. However, the system's momentum remains conserved.

The principle of impulse and momentum can be applied to individual particles during the deformation and restitution phases.

The coefficient of restitution, which represents the ratio of the restitution impulse to the deformation impulse, can also be calculated based on the initial and final velocities of the particles.