Final answer:
The correct unit for linear momentum is kg·m/s. It is calculated by multiplying an object's mass (in kg) with its velocity (in m/s), and it describes how difficult it is to stop the object. Newton's second law connects the change in momentum to the net external force applied over time.
Step-by-step explanation:
The correct unit for linear momentum is kilogram meters per second, denoted as kg·m/s. Linear momentum is a fundamental concept in physics, particularly under the branch of mechanics. It is defined as the product of an object's mass (m) and its velocity (v), given by the equation P = mv. This physical quantity describes the motion of an object and how difficult it is to bring the object to a stop.
The SI unit for mass is kilograms (kg) and for velocity is meters per second (m/s), which makes the unit of linear momentum kg·m/s. For example, the momentum of a 2000-kg elephant charging at a speed of 7.50 m/s is calculated as P = (2000 kg)(7.50 m/s), giving a momentum of 15000 kg·m/s. Such examples help to illustrate the concept of momentum in a tangible context.
According to Newton's second law of motion in terms of momentum, the net external force acting on a system, Fnet, is equal to the change in momentum of the system (Δp) divided by the change in time (Δt) over which the force is applied. This relationship can be used to calculate forces involved when the momentum of an object changes.