Fundamentals of Mechanics – Definition Check What is the correct term for the force by which a body is attracted toward the center of the Earth due to gravity?

Introduction / Context:
In elementary mechanics, different physical quantities describe different aspects of motion and interaction. This question tests your ability to distinguish “weight” from related terms such as mass, momentum, and impulsive force, all of which have precise meanings in physics and engineering.

Given Data / Assumptions:

• A body is near Earth’s surface.
• Gravitational field is approximately uniform (g ≈ 9.81 m/s^2).
• We use standard engineering definitions: mass in kilograms (kg), force in newtons (N).

Concept / Approach:
Weight is the gravitational force acting on a body. It depends on the local gravitational acceleration and the mass of the object. By contrast, mass is a measure of inertia, momentum relates mass and velocity, and an impulsive force acts over a short time interval to change momentum.

Step-by-Step Solution:
Define weight: W = m * g (units: newton). Mass is not a force: it is an intrinsic property (kg). Momentum: p = m * v (units: N·s), not a force. Impulsive force is a large force over short Δt; impulse J = ∫F dt changes momentum. Therefore, the force pulling a body toward Earth’s center is weight.

Verification / Alternative check:
Consider a 10 kg object: W = 10 * 9.81 ≈ 98.1 N directed toward Earth’s center. This matches everyday experience (scale reading) and is consistent with Newton’s law of universal gravitation in a near-surface approximation.

Why Other Options Are Wrong:
impulsive force: describes a short-duration force effect, not continuous gravity. mass: a scalar measure of matter, not a force. momentum: product of mass and velocity, not a force. inertia: tendency to resist acceleration; not a force and not listed in the original options but included here for contrast.

Common Pitfalls:
Confusing mass with weight; remember units (kg vs N). Ignoring that weight changes slightly with location (g varies), while mass does not.

Final Answer:
weight