Final answer:
Force is measured in Newtons (N), which is the SI unit of force equivalent to 1 kg·m/s². In the United States, the pound (lb) is commonly used, with 1 N equaling 0.225 lb. A 225-lb person weighs about 1000 N due to Earth's gravitational force.
Step-by-step explanation:
Force is measured in Newtons (N), which is the SI unit of force. The definition of a newton is 1 kg·m/s², which can also be described using Newton's Second Law of Motion as F = ma, where force equals mass times acceleration. While globally the newton is the standard unit of measure, in the United States, people often use the pound (lb) to describe force, where 1 N is equivalent to 0.225 lb.
When discussing weight and gravitational force, we often refer to an object's weight in newtons. For example, a person weighing 225 lb on Earth is experiencing a weight force of approximately 1000 N. This is calculated using the acceleration due to Earth's gravity, which is approximately 9.80 m/s².