In basic physics, an object that has the capability to do work is said to possess which physical quantity?

Introduction / Context:
The concept of work and energy is central to all branches of physics. Work is done when a force causes displacement, and any system that can perform work is considered to have energy. This question asks you to recall the fundamental definition of energy as the capacity or capability to do work. Recognising this definition helps in understanding many later topics such as potential energy, kinetic energy, thermal energy, and conservation of energy in physical processes.

Given Data / Assumptions:
• The question refers to the general capability of an object to do work. • No specific type of energy (such as kinetic or potential) is mentioned. • Several physical quantities are listed as options: inertia, force, pressure, energy, and momentum.

Concept / Approach:
In physics, energy is formally defined as the capacity to do work. If an object or system can bring about change, cause movement, or exert a force over a distance, it is said to have energy. For example, a lifted weight has gravitational potential energy, a moving car has kinetic energy, a compressed spring has elastic potential energy, and a charged battery has chemical energy. None of the other listed quantities (inertia, force, pressure, momentum) match the exact definition of capacity to do work. Therefore, the correct choice is energy.

Step-by-Step Solution:
Step 1: Recall that work in physics is defined as force multiplied by displacement in the direction of force. Step 2: Recognise that any object capable of doing work must be able to cause displacement by exerting a force. Step 3: Remember the standard textbook definition: energy is the capacity to do work. Step 4: Compare this definition with the wording in the question and identify the matching term. Step 5: Conclude that the quantity describing the capability to do work is energy.

Verification / Alternative check:
Consider examples from everyday life. A charged battery can run an electric device, a stretched bow can shoot an arrow, and a moving vehicle can push another object. In each case, the system possesses energy and therefore has the ability to do work on something else. When the energy is transferred or transformed, work is done. This practical understanding aligns perfectly with the formal definition, confirming that the word energy is the correct choice.

Why Other Options Are Wrong:
Option a (Inertia): Inertia is the tendency of a body to resist changes in its state of motion, not its capacity to do work. Option b (Force): Force is an interaction that can cause acceleration, but by itself it is not described as a stored capability; energy is the stored capacity. Option c (Pressure): Pressure is force per unit area and describes how force is distributed, not the ability to perform work. Option e (Momentum): Momentum is the product of mass and velocity and relates to motion and impulse, not directly to the capacity to do work.

Common Pitfalls:
Students sometimes confuse force and energy because both appear in the definition of work. However, force is an instantaneous interaction, whereas energy represents stored capability. Another common misconception is to think of momentum as energy because both increase with speed, but they have different definitions and units. To avoid confusion, remember that when you see the phrase capacity or capability to do work, the precise physics term is always energy.

Final Answer:
An object that can do work is said to possess Energy.