Force impulse refers to the change in momentum of an object when a force is applied over a specific time period. It is calculated by multiplying the force exerted by the duration of time the force acts. This concept is crucial in understanding how objects respond to forces in motion. In physics, impulse is represented by the equation J = F \cdot t , where J is impulse, F is force, and t is time. The resulting impulse is equal to the change in momentum, which helps explain various phenomena, such as how a baseball accelerates when hit by a bat.