Physics Lecture Notes: Force, Motion, and Energy

Comprehensive vocabulary flashcards covering the fundamental concepts of physics, including motion, energy, electricity, and the scientific method as presented in the lecture notes.

Physics

The branch of science that is concerned with the nature and properties of matter and energy.

Standard Unit of Momentum

$$kgm/s$$

Scalar quantities

Quantities described by magnitude only.

Vector quantities

Quantities that require both magnitude and direction.

Resultant

In vector addition, the line drawn from the tail of the first vector to the head of the last vector.

Acceleration due to gravity ($g$)

The constant acceleration of a falling body, valued at $9.8\,m/s^2$.

Projectile Motion

A combination (resultant) of horizontal and vertical motion.

Uniform Circular Motion Velocity

Velocity that is directed straight out and tangent to the circle.

Newton's First Law (Law of Inertia)

An object at rest remains at rest and an object in motion remains in motion in a straight line with constant speed unless acted upon by an external, unbalanced force.

Newton's Second Law (Law of Acceleration)

Force is directly proportional to mass and acceleration ($F = ma$).

Newton's Third Law (Law of Interaction)

For every action, there is an equal and opposite reaction.

Friction

The resistance of an object when its surface is directly rubbing the other's surface.

Static Friction

Friction that exists when there is no relative motion between two bodies, such as a book on a desk.

Kinetic Friction

Friction that opposes an object as it slides.

Newton's Law of Universal Gravitation

The law stating everything pulls on everything else with a force ($F_g = G \frac{m_1m_2}{d^2}$) depending on their masses and the distance between them.

Gravitational constant ($G$)

$$6.67 \times 10^{-11}\,Nm^2/kg^2$$

Density

The amount of matter per unit volume ($d = \frac{m}{v}$).

Kinetic Energy

The energy of a moving object, calculated as $KE = \frac{1}{2}mv^2$.

Potential Energy

Energy at rest; examples include chemical, gravitational, and stored mechanical energy.

Speed of light ($c$)

$$3 \times 10^8\,m/s$$

Conduction

Heat transfer that occurs when two objects with differing temperatures come into contact, flowing from warmer to colder.

Convection

Heat transfer occurring when warmer areas of liquid or gas rise to cooler areas, causing circulation.

Work

The measure of energy transfer that occurs when an object is moved over a distance by an external force ($work = force \times distance$).

Momentum

The product of an object's mass and its velocity ($momentum = mass \times velocity$).

Impulse

The change in momentum, calculated as $force \times time$.

Elastic Collision

A collision where objects move separately and kinetic energy is conserved.

Perfectly Inelastic collision

A collision where objects move together as a single combined mass after the impact ($m_1v_{i1} + m_2v_{i2} = (m_1 + m_2)v_f$).

Current ($I$)

The rate of flow of charges, measured in amperes.

Resistance ($R$)

The opposition to the flow of charges, measured in ohms.

Voltage ($V$)

The potential difference that causes charges to flow, measured in volts.

Ohm's Law

The principle stating that voltage is the product of current and resistance ($V = IR$).

Series Circuit

A circuit where current has only one path and remains the same in all components ($I_{total} = I_1 = I_2 = I_3$).

Parallel Circuit

A circuit with more than one current path where voltage is the same across all branches ($V_{total} = V_1 = V_2 = V_3$).

Manipulated (Independent) Variable

The variable in an experiment that is intentionally changed.

Responding (Dependent) Variable

The variable that changes because of the manipulated variable.

Refraction

The bending of waves, such as light or sound, as they pass from one transparent substance into another.

Alpha radiation

Fast-moving helium atoms with high energy that can be stopped by a piece of paper.

Gamma rays

High-energy photons that can penetrate several inches of lead.