In a uniform gravitational field near Earth's surface, the center of gravity of a load is best defined as which of the following?

• A. The point where the resultant gravitational force (weight) of the load can be considered to act.
• B. The point that must lie outside the load for any extended object.
• C. The point where the net external force on the load is always zero.
• D. The point where the load has maximum gravitational potential energy.

Answer: (A)

Verified step by step guidance

1. Understand that the center of gravity of a load in a uniform gravitational field is the point at which the entire weight of the load can be considered to act.
2. Recall that the gravitational force on an object is the resultant force due to gravity acting on all its parts, and the center of gravity is the effective point of application of this force.
3. Note that in a uniform gravitational field, the center of gravity coincides with the center of mass because gravity acts equally on all parts of the object.
4. Recognize that the center of gravity can lie inside or outside the object depending on its shape and mass distribution, so it is not necessarily outside the load.
5. Understand that the center of gravity is not defined as the point where the net external force is zero, nor as the point of maximum gravitational potential energy, but specifically as the point where the resultant gravitational force acts.