Physics Lecture Notes: Basic Physical Phenomena

Practice flashcards covering light properties, convex lenses, acoustics, force mechanics, and basic electrical circuits.

What is defined as a light source (光源)?

An object that produces light itself, such as the sun, electric bulbs, or candle flames.

According to the Law of Reflection, what is the specific relationship between the angle of incidence and the angle of reflection?

The angle of incidence and the angle of reflection are always equal.

What are the three main characteristics of an image (像) formed in a mirror?

The image is at a position symmetrical to the object relative to the mirror surface, its size is equal to the object, and its left and right are reversed compared to the object.

When light enters water or glass from air, how does the angle of refraction compare to the angle of incidence?

The angle of refraction is smaller than the angle of incidence, expressed as $\text{Angle of incidence} > \text{Angle of refraction}$.

Under what condition does total internal reflection (全反射) occur when light travels from water into air?

It occurs when the angle of incidence becomes $48.5^{\circ}$ or more, resulting in no refracted light and only reflected light.

What is the focal point (焦点) of a convex lens?

The point on the lens axis where light rays entering parallel to the axis concentrate after being refracted by the lens surface.

What path does a light ray take when it passes through the exact center of a convex lens?

The light ray travels straight through the center without being bent or refracted.

What is a real image (実像) in terms of its properties and orientation?

It is an image formed where light rays actually gather on a screen, and it is oriented upside down and left-right reversed (倒立) relative to the object.

Where is the image formed if an object is placed at a distance exactly twice the focal length from a convex lens?

The image is formed at a position exactly twice the focal length on the opposite side of the lens and is the same size as the object.

What is a virtual image (虚像) such as the one seen through a magnifying glass?

An image where light does not actually gather; it appears in the same orientation as the object (正立) and is always larger than the object.

What are the approximate speeds of sound in air and water as stated in the lecture notes?

Approximately $340\,\text{m/s}$ in air and approximately $1500\,\text{m/s}$ in water.

How is frequency (振動数) defined and what is its official unit?

Frequency is the number of times a sound source vibrates in one second, and its unit is the hertz ($\text{Hz}$).

How do the length and thickness of a string influence the pitch of the sound produced?

A shorter string and a thinner string both contribute to producing a higher-pitched sound.

What are the three categories of force's effects (力のはたらき) on an object?

Changing the shape of an object, supporting an object, or changing the object's state of motion.

How is weight (重さ) defined in the context of gravitational force?

Weight is defined as the magnitude of the gravitational force (重力) acting on an object.

According to the notes, a force of $1\,\text{N}$ is approximately equal to the gravitational force acting on an object of what mass?

A mass of approximately $100\,\text{g}$.

What is Hooke's Law (フックの法則)?

The law stating that the extension of a spring is directly proportional to the magnitude of the force acting on it.

What are the three elements of force (力の三要素) used for arrow representation?

The point of application (作用点), the direction of the force, and the magnitude of the force.

What three conditions must be met for two forces acting on an object to be in equilibrium (つり合い)?

The two forces must be on the same straight line, act in opposite directions, and have equal magnitudes.

In a series circuit (直列回路), what is the rule regarding the strength of the current?

The strength of the current remains equal at all parts throughout the series circuit.