Name: free-fall acceleration on earth
Uploaded: 2023-09-22T11:49:39.000Z
Duration: 55 s
Channel: JoVE

Wyobraźmy sobie kobietę pchającą wózek bagażowy podczas ruchu. Wywierana przez nią siła zewnętrzna rozpędza wózek w kierunku przyłożonej siły.
Jeśli pchnie z większą siłą, wózek będzie się poruszał szybciej. Aby zatrzymać wózek, musi przyłożyć siłę zewnętrzną w kierunku przeciwnym do jej ruchu.
Jeśli umieści więcej bagażu na wózku, ta sama siła wytwarza mniejsze przyspieszenie w kierunku wypadkowej siły zewnętrznej.
Zestawiając je, otrzymujemy drugą zasadę dynamiki Newtona, która mówi, że obiekt przyspiesza proporcjonalnie i w kierunku wypadkowej siły zewnętrznej i odwrotnie do swojej masy.
Lub wypadkowa siła zewnętrzna działająca na obiekt jest iloczynem jego masy i przyspieszenia. Wszystkie przyspieszające obiekty podlegają drugiemu prawu Newtona.

przyspieszenie grawitacyjne na ziemi

Druga zasada Newtona jest ściśle związana z jego pierwszą zasadą ruchu. Matematycznie przedstawia związek przyczynowo-skutkowy między siłą a zmianami ruchu. Drugie prawo Newtona ma charakter ilościowy i jest szeroko stosowane do obliczania tego, co dzieje się w sytuacjach, w których występuje siła. Wszystkie siły zewnętrzne działające na układ sumują się, tworząc siłę wypadkową Fnetto. Większa wypadkowa siła zewnętrzna powoduje większe przyspieszenie. Przyspieszenie to jest wprost proporcjonalne do siły zewnętrznej działającej na układ i ma ten sam kierunek.

Ponadto wydaje się racjonalne, że przyspieszenie powinno być odwrotnie proporcjonalne do masy układu. Innymi słowy, im większa masa (bezwładność), tym mniejsze przyspieszenie wytwarzane przez daną siłę. Eksperymenty wykazały, że przyspieszenie jest dokładnie odwrotnie proporcjonalne do masy, tak jak jest wprost proporcjonalne do wypadkowej siły zewnętrznej. Stwierdzono, że przyspieszenie obiektu zależy wyłącznie od wypadkowej siły zewnętrznej i masy obiektu. Połączenie tych dwóch proporcjonalności daje drugie prawo Newtona, które stwierdza: przyspieszenie układu jest wprost proporcjonalne i ma ten sam kierunek co wypadkowa siła zewnętrzna działająca na układ oraz jest odwrotnie proporcjonalna do jego masy.

Drugie prawo opisuje, jak ciało reaguje mechanicznie na otoczenie. Wpływ środowiska to siła wypadkowa, reakcją ciała jest przyspieszenie, a siła reakcji jest odwrotnie proporcjonalna do masy.

Newton nakreślił także swoje drugie prawo dotyczące pędu: chwilowa szybkość zmian pędu ciała jest równa wypadkowej sile działającej na to ciało.

Ten tekst jest adaptacją <a href="https://openstax.org/books/university-physics-volume-1/pages/5-3-newtons-drugie-law">Openstax, University Physics, tom 1, sekcja 5.3: Drugie prawo Newtona.</a>

Przyspieszenie grawitacyjne na Ziemi

Drugie prawo Newtona jest ściśle związane z jego pierwszą zasadą dynamiki. Matematycznie podaje związek przyczynowo-skutkowy między siłą a zmianami ...

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Acceleration due to Gravity on Earth

free-fall acceleration on earth

Free-fall acceleration on Earth describes how fast an object speeds up when gravity is the only force acting on it. Near Earth’s surface, this acceleration is nearly constant for many everyday situations.

Gravity pulls objects toward Earth and gives them downward acceleration. This motion is often written as g, and it helps explain why falling objects gain speed as they move downward.

The value of g is commonly used in physics to predict the motion of objects dropped or released near the ground. It is an important idea for understanding motion on Earth and for solving basic mechanics problems.

Free-Fall Acceleration on Earth

introduction to scalers

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vector or cross product

Cross Product of Two Vectors

The cross product of two vectors gives a new vector that is related to both original vectors. It is also called the vector product. In many physics problems, this operation helps describe quantities that depend on direction as well as size. The result of a cross product has a direction set by the two input vectors. It is not the same as ordinary multiplication. The transcript focuses on the vector or cross product as a core vector operation students use when working with vectors in science.

introduction to vectors

Vectors in Motion and Direction

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units and standards of measurement

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accuracy and precision

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rules of significant figures

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random and systematic errors

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position and displacement

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Position and displacement are key ideas in straight-line motion. Position tells where an object is located compared with a chosen starting point, called the origin. Displacement describes how far and in what direction the object has moved from its starting position. These ideas help describe motion clearly. Position can change as an object moves. Displacement focuses on the change in position, not just the path taken. That makes it useful for comparing motion in a simple and precise way.

position and displacement vectors

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mass and weight

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acceleration due to gravity on earth

Free-fall acceleration on Earth describes how fast an object speeds up when gravity is the only force acting on it. Near Earth’s surface, this acceleration is nearly constant for many everyday situations. Gravity pulls objects toward Earth and gives them downward acceleration. This motion is often written as g, and it helps explain why falling objects gain speed as they move downward. The value of g is commonly used in physics to predict the motion of objects dropped or released near the...

tension

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gravitational force

How Gravity Acts Between Objects

Gravity is a force that pulls objects toward one another. On Earth, this force gives objects weight and keeps people, water, and other materials from drifting away. It also helps explain why planets and moons stay in motion around larger bodies. The strength of gravitational force depends on the masses of the objects involved. Larger masses create a stronger pull, while smaller masses create a weaker one. The distance between objects also matters, because gravity becomes weaker as objects move...

key terms and concepts

Learn how free-fall acceleration near Earth works, why gravity makes falling objects speed up, and how g is used in basic physics problems.

Free-Fall Acceleration on Earth | JoVE K12

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Free-Fall Acceleration on Earth

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