Linear momentum is defined as which of the following?

Linear momentum is defined as the product of an object's mass and its velocity. This relationship can be mathematically expressed as momentum (p) equals mass (m) multiplied by velocity (v), or p = mv. This definition directly stems from Newton's second law of motion, which underlines that an object in motion retains its momentum unless acted upon by a net external force.

Understanding momentum is crucial because it is a vector quantity, meaning it has both magnitude and direction. The greater the mass or the velocity of the object, the greater its momentum. This concept is vital in analyzing collisions and various motion scenarios in physics.

The other definitions provided do not pertain to linear momentum. The sum of forces acting on an object describes net force rather than momentum. The average speed of an object over time is a measure of distance traveled divided by time, which does not take into account the vector nature of motion. Finally, the change in velocity per unit time refers to acceleration, which is related to momentum but not the same concept.