Answer:
D) the product of an object's mass and its change in velocity
Step-by-step explanation:
The impulse is defined as:
(1)
Where I is the impulse, F is the force and t is the time whereby the force will be applied on the object.
By using Newton's second law, the impulse can be related with the mass and the change in velocity as a consequence of the acting force:
(2)
Where F is the force, m is the mass and a is the acceleration.
The acceleration can be determined using the equations for a Uniformly Accelerated Rectilinear Motion:
(3)
Where
is the change in velocity (
) and
is the interval of time (
)
Remember that the acceleration is defined as the change in velocity in an interval of time.
By replacing equation (3) in equation (2) it is gotten:


But
is the impulse according with equation (1), therefore:

So what best describes an impulse acting on an object is the product of an object's mass and its change in velocity.