Name: how mass and speed affect kinetic energy
Uploaded: 2025-05-22T09:05:47.000Z
Duration: 1 min 14 s
Channel: JoVE

K12 Standards

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

NC K-12 Science Standard Course of Study

9-12

Physical Science

Energy

PS.PSc.7.2

Types of Kinetic Energy

運動エネルギー自体も、機械的、電気的、熱的、放射的なエネルギーなど、さまざまな形で存在します。
機械エネルギーが移動中の自動車のように物体の機械的な動きによるものであるのに対し、電気エネルギーは落雷に見られるように電荷の流れによって構成されます。運動エネルギーが太陽光からのエネルギーなどの電磁波の形をとっている場合、それは放射エネルギーです。
熱エネルギーは、物体内の原子や分子の運動に関連する運動エネルギーです。物体内の原子や分子が素早く移動または振動し、互いに衝突する頻度が高くなると、物体の温度が上昇する。燃える炎からの熱は熱エネルギーの一例です。
これらの原子や分子の振動や動きが遅くなると、逆のことが起こります。その場合、物体は冷たく、水が凍るときのように熱エネルギーが低いと言われます。

運動エネルギーの種類

物体の運動エネルギーの量は、その質量と速度によって異なります。 質量の異なる 2 つのボールが傾斜面を同じ速度で転がり落ちると考えてください。 ボールが重いほど、運動エネルギーは大きくなります。 同様に、同じ質量の 2 つのボールが異なる速度で傾斜面を転がり落ちる場合、より速く動くボールの方がより多くの運動エネルギーを持ちます。

運動エネルギーには、機械エネルギー、電気エネルギー、放射エネルギー、熱エネルギーなど、いくつかの異なる形式があります。 機械エネルギーは物体の運動に関係します。 物体が速く動くほど、より多くの機械的エネルギーが発生します。 たとえば、銃から発射される弾丸やダムを流れる水は、機械的エネルギーの例です。 電気エネルギーは、雷雨中の落雷や電気回路やデバイスで観察されるように、電荷の流れに起因します。 放射エネルギーは、電磁波として伝わり、光と熱の形で体感できる運動エネルギーの一種です。 太陽光は放射エネルギーの一例です。

熱エネルギーは、原子や分子のランダムな動きに関連しています。 温度は、物体内の粒子の平均運動エネルギーの尺度です。 物体の原子や分子が速く動いたり振動したりすると、平均運動エネルギーが高くなり、物体の温度が高くなります。 原子や分子がゆっくり動いているときは、平均運動エネルギーが低くなり、物体の温度も低くなります。 したがって、物体の温度変化を通じて熱エネルギーを観測することができます。 化学反応や相変化 (融解や蒸発など) が発生しないと仮定すると、物質サンプル内の熱エネルギー量が増加すると、その温度が上昇します。 同様に、物質のサンプル内の熱エネルギーの量が減少すると、その温度が低下します。

このテキストは <a href="https://openstax.org/books/chemistry-2e/pages/5-1-energy-basics">から改変されたものです。Openstax, Chemistry 2e, Section 5.1: Energy Basics</a>.

物体の運動エネルギーの量は、その質量と速度に依存します。異なる質量の2つのボールが同時に傾斜面を転がり落ちると仮定します...

Education

JoVE Core

Physics

物理学

Unit 1

ユニット1

Work and Kinetic Energy

仕事と運動エネルギー

KEY TERMS AND CONCEPTS

主要用語と概念

how mass and speed affect kinetic energy

Kinetic energy depends on an object’s mass and speed. A heavier object moving at the same speed has more kinetic energy than a lighter one. An object moving faster also has more kinetic energy when the mass stays the same.

The transcript also describes several forms of kinetic energy. Mechanical energy is linked to the motion of an object. A bullet fired from a gun and water flowing down a dam are examples of mechanical energy.

Electrical energy comes from the flow of electric charges. Lightning during a thunderstorm is one example, and electrical circuits and devices are others. Radiant energy travels as electromagnetic waves and can be experienced as light and heat. Sunlight is an example of radiant energy.

Thermal energy is related to the random motion of atoms and molecules. Temperature measures the average kinetic energy of the particles in an object. When atoms and molecules move or vibrate quickly, the object has a higher average kinetic energy and a higher temperature. When they move more slowly, the average kinetic energy and temperature are lower. If no chemical reaction or phase change occurs, adding thermal energy raises temperature, and removing thermal energy lowers it.

How Mass and Speed Affect Kinetic Energy

work

Work in Physics: Force and Motion

Work in physics connects force, motion, and energy transfer. Work is done when a force acts on an object and that object moves from one position to another. If there is no displacement, no work is done, even if a force is present. The amount of work depends on the force and the direction of motion. For a very small displacement, the work done is written as the dot product of force and displacement vectors. That means work depends on the size of the vectors and the angle between them. You can...

positive, negative, and zero work

How Force Direction Changes Work

Work in physics depends on the direction of a force and the way an object moves. Work is done when energy is transferred to an object. It happens when a force acts on a body that moves from one position to another. The work done by a force is defined as the integral of the force with respect to displacement along the path. Forces can change with position, and an object can move along different paths between the same two points. In vector form, the size of a force times the cosine of the angle...

energy

Energy Sources and Forms in Matter

Energy in matter comes from the Sun and changes form in many everyday processes. The universe is made of matter in different forms, and all forms of matter contain energy. On Earth, many energy sources can be traced back to the Sun, which is the ultimate energy source. Plants capture light energy from the Sun during photosynthesis and convert it into chemical energy. This stored energy can then be used in several ways. People get energy from plant foods, and wood or coal, which are fossilized...

types of potential energy

Potential Energy Examples in Everyday Physics

Potential energy is stored energy, and it appears in several everyday forms. It is also called energy at rest because it is ready to be used later. In physics, different systems can store energy in different ways. Gravitational potential energy is the energy stored by an object because of its position. An apple hanging from a tree is one clear example. Electrical potential energy is stored when electric charges attract or repel each other. Chemical potential energy is stored in the bonds...

types of kinetic energy

Kinetic energy depends on an object’s mass and speed. A heavier object moving at the same speed has more kinetic energy than a lighter one. An object moving faster also has more kinetic energy when the mass stays the same. The transcript also describes several forms of kinetic energy. Mechanical energy is linked to the motion of an object. A bullet fired from a gun and water flowing down a dam are examples of mechanical energy. Electrical energy comes from the flow of electric charges.

kinetic energy - i

Motion Energy in Collisions

Kinetic energy is the energy of motion. It depends on how fast an object moves, not on the direction of its velocity. In classical mechanics, this idea helps explain how moving bodies affect other bodies during collisions. A classic example is a perfectly elastic, head-on collision between two identical bodies, with one body initially at rest. After the collision, the first body stops, and the second body moves away with the first body's original velocity. This same pattern can be seen in...

kinetic energy - ii

Kinetic Energy, Momentum, and Reference Frames

Kinetic energy depends on mass, speed, momentum, and the frame of reference. For a particle, it is one-half of the particle’s mass times the square of its speed. The same idea can also be written in terms of mass and momentum instead of mass and velocity. The units of kinetic energy are mass times speed-squared. These units match the units of work. Force times distance also gives the same units, so kinetic energy and work are measured in joules. That is why work and kinetic energy are two...

work-energy theorem

Work Done and Kinetic Energy

Work done by the net force is linked to an object's kinetic energy. In physics, the net force is the total force acting on an object. Kinetic energy is the energy of motion. The work-energy theorem states that the work done by all forces on an object equals the change in its kinetic energy. This relationship is useful when acceleration is not constant. If the change in velocity is known, the theorem can still help calculate the work done by a force. It connects force, motion, and energy in a...

work and energy for variable forces

Variable Force Work via Graphs and Energy

Variable force work and energy can be found by using force-displacement graphs and the work-energy principle. When a force changes as an object moves, the calculation is more complex than for a constant force. Work is the product of force and displacement, and energy is the capacity of a system to do work. For a constant force, work is found by multiplying the force by the distance moved in the direction of the force. For a variable force, the work done is the area under the force-displacement...

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work-energy theorem for motion along a curve

work-energy-theorem-for-motion-along-a-curve

Work-Energy Along Curved Paths

The work-energy theorem can be applied to motion along a curved path. A curved path can be treated as many tiny straight paths added together. On each small part, the force can be taken as constant, so the work-energy theorem can be used there. The total result comes from adding the work done along all of those small path segments. The net work is found with an integral, which adds the work from each infinitesimal path. The total change in kinetic energy is the sum of the changes along the way.

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work done over an inclined plane

Gravity and Work on Sloped Motion

Gravity and work on sloped motion can be described with the center-of-mass framework. For a rigid body, internal forces do no work, so they can be ignored. The work-energy theorem then uses only the external forces. The work done by gravity depends on the path of the body’s center of mass. If gravity helps increase kinetic energy, the work is positive. If an object is lifted against gravity, the work is negative because kinetic energy decreases. For horizontal motion, the work done by or...

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work done by many forces

Calculating Work from Multiple Forces

Calculating work from multiple forces can be done in two ways, and both methods give the same result. One method finds the work done by each force first. The other method finds the net force by adding the force vectors first.

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work done by gravity

Gravity and Positive vs Negative Work

Gravity is one of the four fundamental forces in nature. On Earth, the force between an object and Earth is called gravity. Gravity does work on an object when it moves the object toward Earth’s center. In that case, the work done by gravity is positive. When an external force lifts an object away from Earth’s center, that force works against gravity. The net work done in this case is negative. If an object moves along the Earth with no change in distance toward or away from Earth’s center,...

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power

Power in Work and Motion

Power connects work with the time needed to do it. Work depends on force and displacement. The work-energy theorem also links net work on an object to the change in its kinetic energy between two points on its path. These ideas do not include time directly, but time still matters in many real situations. A sprinter is a clear example. Two runners may reach the same finish speed, so they do the same amount of work. The winner is the one who reaches that speed in less time. Power describes this...

power expended by a constant force

Power as the Rate of Doing Work

Power describes how fast work is done. In physics, two sprinters can cross the finish line with the same velocity and do the same amount of work, but the one who finishes first has greater power because the work takes less time. Average power is the work done during a time interval divided by that time interval. When the time interval becomes very small, this becomes instantaneous power. That gives the power at a specific moment instead of over a longer stretch of time. Power can also be...

key terms and concepts

Explore how mass and speed change kinetic energy, plus examples of mechanical, electrical, radiant, and thermal energy for high school science.

How Mass and Speed Affect Kinetic Energy | 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。

PS.Phy.6.1

Pennsylvania State Academic Standards

3.2.9-12.P

3.2.9-12.Q

Louisiana Student Standards for Science

High School

Chemistry

HS-PS3-3

HS-PS3-2

HS-PS3-1

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Energy And Waves

Conservation of energy

Tennessee Academic Standards

PHYS.PS3.1

CHEM1.PS3.1

Minnesota Academic Standards in Science

2.2.1 9P.2.2.1.1

new-jersey-student-learning-standards-for-science

New Jersey Student Learning Standards for Science

Alabama Course of Study Science

9-12.PS.1.1

9-12.PS.1.1.a

9-12.P.2.3.b

Next Generation Science Standards

Florida Department of Education

SC.912.P.10

SC.912.P.10.1

SC.912.P.12

SC.912.P.12.9

Texas Essential Knowledge and Skills

PHYS.7

PHYS.7.B

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

South Carolina College and Career Ready Science Standards

P-PS3-3

new-york-state-science-learning-standards

New York State Science Learning Standards

HS. Energy

HS-PS3-1.

Georgia Standards of Excellence

SPS7.

Types of Energy

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PS.PSc.7.1

The universe is composed of matter in different forms, and all forms of matter contain energy.&#160; The different forms of energy on Earth originate from ...

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The amount of kinetic energy of an object depends on its mass and speed. Consider two balls of different masses rolling down an inclined plane at the same ...

Conservation of Mechanical Energy

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Conservation of Energy

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Conservation of Energy: Application

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Use mathematics and computational thinking to explain the Law of Conservation of Energy in a mechanical system in terms of kinetic and potential energy.

Work

Work is done when energy is transferred from one object to another. In other words, work is when a force acts on something that undergoes a displacement ...

Positive, Negative, and Zero Work

Work is done on an object when energy is transferred to the object. In other words, work is done when a force acts on a body that undergoes a displacement ...

Work-energy Theorem

According to Newton&#x2019;s second law of motion, the sum of all the forces acting on a particle (net force) determines the rate of change in the ...

Work and Energy for Variable Forces

When an object is acted upon by a variable force, the amount of work done and the change in energy of the object can be more complex to calculate compared ...

Work-Energy Theorem for Motion Along a Curve

The work-energy theorem can be generalized to the motion of a particle along any curved path. The simple argument here is that the curved path can be ...

Work Done Over an Inclined Plane

The center-of-mass framework helps to easily describe the work done on rigid bodies. Since the internal forces in a rigid body do no work, they can be ...

Work Done by Many Forces

The total work done on an object acted upon by multiple forces can be computed using two methods that give the same result. In one method, the work done ...

Work Done by Gravity

Gravitation is one of the four fundamental forces in nature. The force between objects on Earth and Earth itself is called gravity.
Like other forces, ...

Use mathematics and computational thinking to explain work in terms of the relationship among the applied force to an object, the resulting displacement of the object, and the energy transferred to an object.

PS.PSc.7.3

Power

The concept of work involves force and displacement; meanwhile, the work-energy theorem relates the net work done on a body to the difference in its ...

Power Expended by a Constant Force

The relationship between work done and the time taken to do it can be explained using the concept of power. For example, several sprinters in a race may ...

Construct an explanation to infer the relationship between work and power, both quantitatively and qualitatively.

PS.PSc.7.4

Analyze energy transfers and transformations within a mechanical system.

How Mass and Speed Affect Kinetic Energy

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