Question

What is necessary for work to be done? Choose the correct statement.
(1) The action of the force is necessary.
(2) Displacement is necessary.
(3) Displacement in the direction of force is necessary.

Answer 1

In physics, a force is any contact that, while unopposed, causes an object to change its velocity. A force can cause a mass item to change its velocity (which includes starting to move from a standstill), i.e. accelerate. Intuitively, force may be characterised as a push or a pull. A force is a vector quantity since it has both magnitude and direction. The SI unit of Newton is used to measure it (N). The letter F is used to indicate force.

Complete answer:
A force is considered to have done work on an object when it operates on it across a long distance. The change in kinetic energy that an item experiences is the labour done on it physically.
Work is the energy delivered to or from an item by applying force along a displacement in physics. It is frequently expressed as the product of force and displacement in its simplest form. When applied, a force is said to produce positive work if it has a component in the direction of the point of application's displacement. If a force has a component that is opposite the direction of displacement at the point of application, it causes negative work. Displacement in the direction of the applied force is required for work to be completed, implying that displacement occurs when force is applied.
When a force operates on a body and causes a displacement of the point of application in the force's direction, it is said to accomplish work. When a force causes movement, it is said to be working.
Work is defined as a change in a system's kinetic energy.

Hence option D is correct.

Note:
The joule (J), named for 19th-century English scientist James Prescott Joule, is the SI unit of work. It is defined as the work necessary to exert a force of one newton through a displacement of one metre. The dimensionally equivalent newton-metre (Nm) is occasionally used as a unit of work measurement, however this should not be confused with the torque measurement unit. The SI authority discourages the use of Nm because it might cause misunderstanding as to whether a number stated in newton metres is a torque measurement or a work measurement.