What is defined as the product of the resultant of all forces acting on a body and the time that the resultant acts?

The product of the resultant of all forces acting on a body and the time that the resultant acts is known as linear impulse. Linear impulse is a crucial concept in mechanics that quantifies the change in linear momentum of an object when a net force is applied over a specific period.

When a force acts on a body, it causes a change in its velocity, and hence, a change in its momentum. The relationship between impulse and momentum is captured in the impulse-momentum theorem, which states that the impulse applied to an object is equal to the change in its momentum. This means that if you know the resultant force acting on an object and the duration of time that force acts, you can determine the impulse imparted to the object, directly correlating to the change in linear momentum.

In contrast, other terms such as angular impulse and angular momentum relate to rotational dynamics rather than linear motion. Linear momentum is the product of the mass of an object and its velocity at a given instant, rather than the integral effect of forces over time. Understanding these distinctions is crucial when applying the right concepts in problems related to dynamics and mechanics.