If a football player running down the field is tackled by another football player who holds onto the first football player so that they both fly out of bounds together, that collision is .

Inelastic

Explanation:

If a football player running down the field is tackled by another football player who holds onto the first football player so that they both fly out of bounds together, that collision is inelastic.

An inelastic collision can be defined as a type of collision in which the total kinetic energy possessed by the colliding bodies doesn't remain the same as a result of internal friction.

This ultimately implies that, in an inelastic collision the maximum amount of kinetic energy possessed by the colliding bodies isn't conserved (kinetic energy is lost) after the collision, this is due to the action of an internal friction.

Mathematically, inelastic collision is given by the formula;

Where;

in physics zero. in muscle fatigue could be high