Forces, Momentum, and Motion

Vocabulary flashcards covering core physics definitions from the lecture notes, including Newton's laws of motion, resultant forces, Hooke's law, momentum, centripetal force, and impulse.

Force

A push or pull that can change an object's speed, direction, shape, or size; it is a vector quantity with the unit of Newton ($N$).

Resultant Force

The single combined force that represents the sum of all multiple forces acting on an object.

Newton's First Law of Motion

The law stating that when the resultant force acting on an object is zero, the object remains at rest (stationary) or continues moving at a constant speed.

Newton's Second Law of Motion

The law stating that if the resultant force acting on an object is not zero, the object accelerates in the direction of the resultant force, formulated as $F = m \times a$.

Hooke's Law

A law that describes the relation between an elastic object (spring) and the load attached to it, formulated as $F = k \times x$.

Spring Constant ($k$)

A measure of spring stiffness formulated as $k = \frac{F}{x}$ and measured in $N/m$, where a larger value means the spring is harder to extend.

Limit of Proportionality

The point on an extension-load graph beyond which Hooke's law does not apply anymore.

Weight ($W$)

The gravitational force acting on a load, calculated by $W = m \times g$, where $g$ is gravity with a value of $9.8\,m/s^2$ or $10\,m/s^2$.

Momentum ($P$)

The product of an object's mass and its velocity, formulated as $P = m \times v$ and measured in units of $kg \cdot m/s$.

Centripetal Force

The force acting on an object moving along a circular path where velocity continually changes direction; the force required becomes smaller as the radius increases and larger as speed increases.

Principle of Momentum

The principle stating that when objects collide, the total momentum before collision is equal to the total momentum after collision.

Impulse ($I$)

The change in momentum of an object, formulated as $I = F \times t$ with units of $N \cdot s$, or alternatively expressed as $I = mv - mu$.