Tenth Grade Physics: Mechanics, Energy, and Gravitation

Vocabulary flashcards based on tenth-grade physics lecture notes covering Newton's three laws of motion, free-body diagrams, work, kinetic and potential energy, conservation principles, and universal gravitation.

Inertia (Newton's First Law)

The law stating that an object only moves when an external force acts on it, expressed as $\sum \vec{F} = 0 \Rightarrow \vec{a} = 0$.

Acceleration / Dinamic Law (Newton's Second Law)

The law stating that the acceleration of an object depends on the net force and its mass, expressed mathematically as $\sum \vec{F} = m \cdot \vec{a}$.

Action and Reaction (Newton's Third Law)

The law stating that every action force has an equal and opposite reaction force acting on another object, represented by $\vec{F}_{A \rightarrow B} = -\vec{F}_{B \rightarrow A}$.

Free-body Diagram

A diagram showing all external forces acting on a single object, commonly including weight ($mg$), normal force ($N$), friction ($f$), and tension ($T$).

Work

The energy transferred by a force when an object moves through a displacement, calculated as $W = F \cdot d \cdot \cos(\theta)$; if an object does not move, there is zero work.

Energy

The capacity of making work.

Kinetic Energy ($E_K$)

Energy associated with an object's motion that increases with mass and the square of speed, defined by the formula $E_K = \frac{1}{2} \cdot m \cdot v^2$.

Gravitational Potential Energy ($E_p$)

Energy associated with an object's position within a gravitational field, expressed as $U = m \cdot g \cdot h$.

Conservation of Mechanical Energy

The principle that when only conservative forces do work, total mechanical energy remains constant ($E_K + E_p = \text{constant}$, or $\frac{1}{2}m v_i^2 + m g h_i = \frac{1}{2}m v_f^2 + m g h_f$).

Momentum ($\vec{p}$)

The measure of motion of an object, defined as the product of its mass and velocity ($\vec{p} = m \vec{v}$).

Conservation of Momentum

The principle stating that in an isolated system with zero net external force, total momentum remains constant ($\sum \vec{p}_i = \sum \vec{p}_f$).

Momentum Conservation for Two Interacting Objects

The relation expressing momentum conservation during an interaction between two objects: $m_1 \vec{v}_{1i} + m_2 \vec{v}_{2i} = m_1 \vec{v}_{1f} + m_2 \vec{v}_{2f}$.

Universal Gravitation

The law describing the gravitational attractive force between two objects of masses $m_1$ and $m_2$ separated by a distance $r$, given by $F_g = G \frac{m_1 \cdot m_2}{r^2}$.

Gravitational Constant ($G$)

The proportionality constant in Newton's law of universal gravitation, equal to $6.674 \times 10^{-11}$.