Physics: Laws of Motion and Mechanics

Comprehensive vocabulary flashcards covering fundamental mechanics and laws of motion from the lecture notes, including inertia, forces, moments, Newton's laws, impulse, and orbital weightlessness.

Inertia (நிலைமம்)

The inherent property of a body to resist any change in its state of rest or its state of uniform linear motion, unless acted upon by an external unbalanced force.

Inertia of Rest (ஓய்வில் நிலைமம்)

The resistance or tendency of an object to resist any change to its state of rest.

Inertia of Motion (இயக்கத்தில் நிலைமம்)

The resistance or tendency of an object to resist any change to its state of uniform motion.

Inertia of Direction (திசையில் நிலைமம்)

The resistance or tendency of an object to resist any change to its direction of motion.

Like Parallel Forces (ஒத்த இணைவிசைகள்)

Two or more forces of equal or unequal magnitude acting along parallel lines in the same direction.

Unlike Parallel Forces (மாறுபட்ட இணைவிசைகள்)

Two or more forces of equal or unequal magnitude acting along parallel lines in opposite directions.

Resultant Force of Opposing Forces (தொகுபயன் விசை)

When two opposing forces $F_1 = 5\,\text{N}$ and $F_2 = 15\,\text{N}$ act simultaneously on an object, the resultant force is $F_{\text{net}} = F_2 - F_1 = 15\,\text{N} - 5\,\text{N} = 10\,\text{N}$, directed along the direction of the greater $15\,\text{N}$ force.

Moment of a Couple (இரட்டையின் திருப்புத்திறன்)

The rotating effect produced by a couple, equal to the product of the magnitude of one of the forces ($F$) and the perpendicular distance ($S$) between the lines of action of the two forces, given by $M = F \times S$ (e.g., opening or closing a water tap).

Principle of Moments (திருப்புத்திறன் தத்துவம்)

When an object is in equilibrium under the action of parallel or antiparallel forces, the total clockwise moment equals the total anticlockwise moment, expressed as $F_1 \times d_1 = F_2 \times d_2$.

Newton's Second Law of Motion (நியூட்டனின் இரண்டாம் விதி)

The force acting on an object is directly proportional to the rate of change of linear momentum of that object, and this change in momentum takes place in the direction of the force, formulated as $F = m \times a$.

Application of Torque in Spanners (திருப்புத்திறன்)

Spanners with long handles are used to tighten nuts in large vehicles because torque is defined as $\tau = F \times d$; increasing the perpendicular distance ($d$) creates a larger turning effect while reducing the applied force ($F$) required.

Impulsive Force Reduction in Cricket Catching

The technique where a cricket fielder pulls their hands backward while catching a fast-moving ball to increase the impact time, thereby significantly reducing the impulsive force exerted on their hands.

Apparent Weightlessness in Orbit (எடையற்ற நிலை)

The phenomenon where an astronaut in an orbiting spacecraft appears to float because both the astronaut and the spacecraft share the same orbital velocity and acceleration, placing the astronaut in a state of free fall with an apparent weight of zero.

Acceleration Calculation via Newton's Third Law

For two bodies with a mass ratio of $M_1 : M_2 = 4 : 3$, applying the same force to accelerate the heavier mass ($M_1 = 4$) at $a_1 = 12\,\text{m/s}^2$ accelerates the lighter mass ($M_2 = 3$) according to $M_1 \times a_1 = M_2 \times a_2$, yielding $a_2 = \frac{4 \times 12}{3} = 16\,\text{m/s}^2$.