Name: understanding force in motion
Uploaded: 2023-04-30T10:52:51.000Z
Duration: 1 min 6 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Physics

motion-and-stability-forces-and-interactions

Motion and Stability- Forces and Interactions

PS.Phy.2.1

Force

私たちは以前、物体の運動を研究してきました。物体が動く原因は何ですか?
「プッシュ」または「プル」が別のオブジェクトによって適用されると、それは動きます。このような物体間、または物体とその周囲の相互作用は力と呼ばれます。
力を決定するには、力がどれほど強く、どの方向に作用するかを知る必要があります。したがって、力はベクトル量であり、ニュートンの単位で表されます。
例えば、地球の中心に向けられた重力によって、果実は地面に落ちます。
1 つのオブジェクトに複数の力が作用する場合、それらの複合効果は、個々の力のベクトル合計に等しい 1 つの力と同じです。この原理は、力の重ね合わせ原理と呼ばれます。
逆に、オブジェクトに作用する力は、その水平方向と垂直方向の力成分に分解できます。

利益相反は宣言されていません。

力は私たちの生活のあらゆる瞬間に影響を与えます。 私たちの体は重力によって地球に引き寄せられ、それらは荷電粒子の力によって結合されています。 ドアを開けたり、道を歩いたり、フォークを持ち上げたり、赤ちゃんの顔に触れたりするとき、私たちは力を加えています。 私たちの体の原子は電気力によって結合されており、原子核と呼ばれる原子の中心は、私たちが知っている中で最も強い力である原子核力によって結合されています。

運動の研究は運動学と呼ばれますが、運動学は物体の移動方法、つまり速度と加速度を説明するだけです。 動力学は、力が物体や系の動きにどのような影響を与えるかを研究するものです。 対象となる物体や系 (系とは分析対象のあらゆるもの) の運動の原因を考慮します。 これを理解するには、力の実際的な定義が必要です。 力の直感的な定義、つまり押すか引くかから始めるのが良いでしょう。 押す力や引く力には、大きさと方向があることがわかっています (したがって、力はベクトル量です)。 したがって、力を特定の大きさと方向で物体を押すまたは引くものとして定義できます。 力はベクトルで表すことも、標準的な力の倍数として表すこともできます。

力の SI 単位はニュートン (N の略称) と呼ばれ、1 N は質量 1 kg の物体を 1 m/s の速度で加速するのに必要な力で 2 : 1 N = 1 kg·m/s2 です。

このテキストは<a href="https://openstax.org/books/university-physics-volume-1/pages/5-introduction"> Openstax, University Physics Volume 1, Section 5.0: Introduction</a> and <a href="https://openstax.org/books/university-physics-volume-1/pages/5-1-forces">Section 5.1: Forces</a> から改変されたものです。

力は私たちの人生のあらゆる瞬間に影響を与えます。私たちの体は力によって地球に固定されており、荷電粒子の力によってまとめられています。私たちが...

Education

JoVE Core

物理学

Unit 1

ユニット1

Newton's Laws of Motion

ニュートンの運動の法則

KEY TERMS AND CONCEPTS

主要用語と概念

understanding force in motion

Force is a push or pull that acts on an object. It has both magnitude and direction, so force is a vector quantity. In everyday life, force appears when we open a door, walk down a street, lift a fork, or touch a baby's face.

Forces also shape matter at the smallest scales. The atoms in our bodies are held together by electrical forces. The nucleus of an atom is held together by nuclear force, which is the strongest force known to us.

The study of motion is called kinematics. Kinematics describes how objects move, including their velocity and acceleration. Dynamics is different because it studies how forces affect the motion of objects and systems. A system is anything being analyzed.

To work with force in physics, we use vectors or compare it with a standard force. The SI unit of force is the newton, written as N. One newton is the force needed to accelerate a 1 kg object at 1 m/s², so 1 N = 1 kg·m/s².

Understanding Force in Motion

force

Force is a push or pull that acts on an object. It has both magnitude and direction, so force is a vector quantity. In everyday life, force appears when we open a door, walk down a street, lift a fork, or touch a baby's face. Forces also shape matter at the smallest scales. The atoms in our bodies are held together by electrical forces. The nucleus of an atom is held together by nuclear force, which is the strongest force known to us. The study of motion is called kinematics. Kinematics...

types of forces

Contact and Field Forces in Physics

Forces in physics are often grouped as contact forces and field forces. Contact forces happen when objects touch directly. Field forces act without direct physical contact. They come from a field, which is a region of space that can be detected by the force it exerts on a body. Scientists describe four fundamental force fields in nature: gravitational, electromagnetic, strong nuclear, and weak nuclear. The gravitational field gives a body its weight. The electromagnetic field includes static...

newton's first law: introduction

Newton's First Law and Inertia

Newton's first law of motion explains inertia and how forces change motion. Motion can be striking to observe, from a dolphin jumping from water to a bird in flight or a satellite moving in orbit. The study of motion is kinematics, which describes velocity and acceleration. Dynamics goes further by examining the forces that affect moving objects and systems. Newton's laws of motion are the foundation of dynamics. They are simple in form, but they describe a wide range of natural behavior.

newton's first law: application

Newton's First Law and Friction

Newton's first law explains why friction changes an object's motion. It says that an object at rest stays at rest, and an object in motion keeps moving unless a net external force acts on it. A net external force is the overall force from outside the object that causes a change in velocity, meaning a change in speed or direction. This idea gives a cause-and-effect reason for motion, rather than just describing what we see. Galileo first developed the idea behind the first law of motion, and...

internal and external forces

External Forces and Motion Changes

External forces and motion changes are linked in Newton’s first law. A net external force causes a change in motion. External forces act on an object or system from outside that object or system. Internal forces come from inside the system of interest. They act on one part of an object and are exerted by another part of the same object. These forces do not cause acceleration when the whole system is studied. When analyzing motion, the internal forces are ignored. Instead, only the external...

newton's second law

Force, Mass, and Acceleration

Newton's second law connects net force, mass, and acceleration. It explains how an object's motion changes when external forces act on it. The law gives a clear cause-and-effect link that can be used to make calculations. All external forces on a system are added together to find the net force, or F net. A larger net external force produces a larger acceleration. The acceleration points in the same direction as the net force. Mass also affects the result. A larger mass means more inertia, so...

mass and weight

Weight Changes, Mass Stays Constant

Mass and weight are related, but they are not the same. In physics, weight is the pull of the Earth on an object. It depends on how far the object is from the center of the Earth. Mass is the amount of matter in an object, and it does not change with location. Everyday language can make this difference confusing. Medical records often list body weight in kilograms, even though the correct force unit is the newton. That can make mass and weight seem interchangeable. In physics, however, they...

weightlessness

Weightlessness in Free Fall

Weightlessness happens when contact forces disappear, even though gravity is still present. In physics, an object in free fall has only gravity acting on it. If the net external force on the object is its weight, the object is accelerating toward the center of the Earth. Galileo showed that, without air resistance, all objects fall with the same acceleration g. On Earth, falling objects are never truly in free fall because air always pushes upward with some resistance force. That is why real...

apparent weight

Scale Readings in Motion and Water

Scale readings can change when an object is moving or submerged in water. The force we call true weight is the gravitational force acting on an object. When motion or fluid forces are present, the reading can differ from that true weight. In water, this changed reading is called apparent weight, and it equals true weight minus the buoyant force. A bathroom scale in an elevator shows how this works. At rest, the scale reads the force the person pushes downward on it. The only forces on the...

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newton's third law: introduction

Newton's Third Law in Force Pairs

Newton's third law explains how force pairs work in motion and interactions. When one body exerts a force on a second body, the first body experiences a force that is equal in magnitude and opposite in direction. A simple example is a person pushing on a wall. The wall pushes back on the person with an equal and opposite force. This is why Newton's third law is often described as action and reaction, where the action is the force exerted and the reaction is the force experienced afterward. <br...

newton's third law: examples

Newton's Third Law in Motion

Newton's third law explains how forces come in pairs during motion. It says that every action has an equal and opposite reaction. In these examples, the two forces act on different systems, so they do not cancel each other out. A swimmer pushing off the side of a pool shows this clearly. The swimmer pushes against the wall with their feet and then accelerates in the opposite direction. The wall pushes back with an equal and opposite force. If the swimmer is the system of interest, the wall's...

drawing free-body diagrams: rules

Free-Body Diagrams for Newton’s Laws

Free-body diagrams help students map the forces acting on an object in physics. They are used often when studying and applying Newton’s laws of motion. A clear diagram makes it easier to analyze a system before solving for motion. Start by drawing the object under consideration. If the object is treated like a particle, show it as a point and place that point at the origin of an x-y coordinate system. Then add every force that acts on the object as a vector. Do not include the net force on the...

free body diagrams: examples

Free Body Diagram Force Examples

Free body diagrams show the external forces acting on an object or system. The object is drawn as a single isolated point, or free body, so the forces are easier to analyze. Only forces that come from outside the object or system are included. These forces are shown as vectors pointing away from the free body. A person sitting on a chair is a simple example. The free-body diagram has two forces. The chair exerts an upward normal force, and gravity pulls downward with the weight. A rocket sled...

inertial frames of reference

Newton's First Law and Reference Frames

Newton's first law helps identify inertial reference frames. An inertial reference frame is one in which Newton's first law holds true. In that frame, an object with no net force moves at constant velocity. A key idea is that any frame moving at constant velocity relative to an inertial frame is also inertial. For that reason, inertial frames can be found by comparing motion from one frame to another. The laws of physics do not give one inertial frame special status over another. In nature, a...

non-inertial frames of reference

Why Motion Seems Different in Accelerating Frames

A non-inertial frame of reference is a frame that accelerates, decelerates, or rotates relative to an inertial frame. In these frames, motion can look unusual because the observer is moving with the system. That is why an airplane taking off, a car turning a corner, a merry-go-round, and a tropical cyclone can all be examples of non-inertial motion. These situations can show inertial forces, which seem to appear because the frame itself is accelerating or rotating. The force does not come from...

centrifugal force

Rotating Frames and Pseudo Forces

Pseudo forces, also called fictitious forces, appear in a rotating frame of reference when compared with an inertial frame. They are not real forces. Instead, they are mathematical tools that help make Newton&amp;#39;s laws of motion easier to use in a non-inertial frame. Common examples include centrifugal, Coriolis, and Euler forces. These forces matter in mechanics, astrophysics, and fluid dynamics. In these areas, motion is often described from a frame that is not inertial. That is why...

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key terms and concepts

Learn how force acts as a push or pull, how it affects motion, and why newtons are the SI unit used to measure force in physics.

Understanding Force in Motion | JoVE K12

physics

JoVE Core 物理学は、運動学、力学、流体力学、静力学、波動、音響などの基礎的な物理学の理論と応用を、簡潔でわかりやすいアニメーション ビデオで紹介します。さらに、科学者の実際のビデオでは、世界中の今日の研究所で行われている古典的および独自の研究実験における関連概念の適用を示しています。

Pennsylvania State Academic Standards

Physical Science

Structure and Properties of Matter

3.2.9-12.A

3.2.9-12.B

3.2.9-12.N

Louisiana Student Standards for Science

High School

Matter And Its Interactions

HS-PS1-1

Motion And Stability: Forces And Interactions

HS-PS2-4

HS-PS2-5

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Forces And Motion

Forces

Forces, Momentum And Motion

newton-s-laws-applied-to-complex-problems

Newton's laws applied to complex problems

Friction force (static and kinetic)

Air resistance and drag

Forces in two dimensions

Tennessee Academic Standards

Motion and Stability: Forces and Interactions

PHYS.PS2.4

Energy

PHYS.PS3.9

Virginia  Standards of Learning

HIgh School

PS.8

PS.8.b

PH.3

PH.3.a

Arizona Science Standards

HS.P3

HS.P3U1.6

Alabama Course of Study Science

waves-and-their-applications-in-technologies-for-information-transfer

Waves and Their Applications in Technologies for Information Transfer

9-12.PS.2.3.a

9-12.P.1.2.a

9-12.P.1.2.b

Next Generation Science Standards

HS-PS2-1

Florida Department of Education

SC.912.P.10

SC.912.P.10.10

Texas Essential Knowledge and Skills

PHYS.5

PHYS.5.F

Chemistry and Physics

IPC.5

IPC.5.B

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

P-PS2-2

P-PS3-5

new-york-state-science-learning-standards

New York State Science Learning Standards

HS. Forces and Interactions

HS-PS2-1.

Georgia Standards of Excellence

SPS8.

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Use models (graphs, equations, diagrams) to infer motion in one dimension.

PS.Phy.1.1

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average-and-instantaneous-velocity-vectors

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principle-linear-impulse-momentum-for-single-particle-problem

Principle of Linear Impulse and Momentum for a Single Particle: Problem Solving

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Non-uniform Circular Motion

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Relative Velocity in One Dimension

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Relative Velocity in Two Dimensions

Relative velocity is the velocity of an object as observed from a particular reference frame, or the velocity of one reference frame with respect to ...

Use models (graphs, equations, diagrams) to infer motion in two dimensions.

PS.Phy.1.2

Analyze the motion of objects using time, distance, displacement, speed, velocity, and acceleration.

Understanding Force in Motion

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