Introduction to Force and Its Properties

Vocabulary terms covering the definition, mathematical derivation, units, and effects of force, as well as the concept of resultant and balanced forces based on the lecture material.

Force

A push or pull that changes or tends to change the state of rest or uniform motion of a body, or changes its direction of motion or shape.

Mathematical Representation of Force

Mathematically, force $F$ is equal to the product of the mass $m$ of a body and acceleration $a$ produced in the body: $F = ma$

Acceleration (a)

The rate of change of velocity, calculated as: $a = \frac{v - u}{t}$

Newton (N)

The SI system unit of force, where $1\,N = 1\,\text{kg} \cdot 1\,\text{m/s}^2$

dyne

The CGS system unit of force, where $1\,\text{dyne} = 1\,\text{g} \cdot 1\,\text{cm/s}^2$

Relation between Newton and dyne

The conversion factor where $1\,N = 10^5\,\text{dyne}$

Deformation

A change in the shape of an object caused by the application of force, such as stretching, compressing, or bending.

Resultant Force

The sum of all individual forces acting on an object at the same time.

Resultant Force (Opposite Direction)

When two forces act in opposite directions, the resultant force is the difference between the two forces.

Resultant Force (Same Direction)

When two forces act in the same direction, the resultant force is the sum of the two forces.

Balanced Forces

Forces acting on a body where the resultant force is zero ($0$), meaning they cannot move an object at rest or change its speed or direction.

Unbalanced Forces

Forces acting on an object where the resultant force is not zero, leading to motion or a change in state.