Hukum Gravitasi Umum Newton | Materi Fisika Kelas 10
Summary
TLDRThis educational video script delves into the concept of gravity, explaining its everyday significance and historical discovery by Newton. It explores how gravity is the force that keeps objects grounded and contrasts the fall of an apple with the non-fall of stars towards Earth due to their vast distances. The script simplifies complex gravitational concepts by comparing the gravitational pull between an apple and the Earth versus that between the Earth and the Moon. It introduces Newton's law of universal gravitation, expressed as F = G (m1 * m2) / r^2, where F is the force of gravity, G is the gravitational constant, m1 and m2 are the masses of the objects, and r is the distance between their centers. The script aims to clarify that gravity is directly proportional to mass and inversely proportional to the square of the distance between objects.
Takeaways
- 🌍 Gravity is the force that keeps objects on the Earth's surface.
- 🍎 Newton's apple story is a common tale about the discovery of gravity, although it's not entirely accurate.
- 🧐 Newton pondered why an apple falls to the Earth but stars don't, leading to his theory of gravitation.
- 🔍 The gravitational force between two objects is inversely proportional to the square of the distance between them.
- 📏 The force of gravity decreases as the distance between objects increases.
- 🌌 Even though stars exert a gravitational pull on Earth, it's very weak due to the vast distance.
- 🍏 If an apple is thrown, it will be attracted to the Earth due to the greater mass of the Earth compared to a human.
- 📚 Newton concluded that the gravitational force is directly proportional to the product of the masses of the interacting objects.
- 🔢 The full equation for gravitational force is F = G × (M1 × M2) / r², where G is the gravitational constant.
- 🌕 An example calculation in the script involves the gravitational force between the Earth and the Moon, using the given formula.
- ⚖️ The gravitational constant (G) was discovered by Henry Cavendish and has a value of 6.67 × 10⁻¹¹ N(m/kg)².
Q & A
What is the primary force that keeps objects on the surface of the Earth?
-Objects remain on the surface of the Earth due to the force of gravity.
Who is credited with the initial concept of gravity as described in the script?
-Sir Isaac Newton is credited with the initial concept of gravity, as he pondered why an apple falls to the Earth but stars do not.
What is the relationship between the gravitational force and the distance between two objects according to Newton's observations?
-Newton observed that the gravitational force between two objects is inversely proportional to the square of the distance between them.
How does the mass of objects influence the gravitational force between them?
-The gravitational force is directly proportional to the product of the masses of the two interacting objects; the larger the masses, the greater the gravitational force.
What is the formula for calculating the gravitational force according to the script?
-The formula for calculating the gravitational force is F = G * (M1 * M2) / r^2, where F is the force, G is the gravitational constant, M1 and M2 are the masses of the two objects, and r is the distance between them.
What is the value of the gravitational constant (G) as mentioned in the script?
-The value of the gravitational constant (G) is 6.67 x 10^-11 N(m^2/kg^2).
Why does an apple fall towards the Earth rather than towards a person standing at the same distance?
-An apple falls towards the Earth due to the much larger mass of the Earth compared to a person, resulting in a stronger gravitational pull.
What is the difference between gravitational force and gravitational acceleration?
-Gravitational force is the force of attraction between two masses, while gravitational acceleration is the acceleration experienced by an object due to the gravitational force, typically 9.8 m/s² or 10 m/s².
How is the gravitational force between the Earth and the Moon calculated?
-The gravitational force between the Earth and the Moon is calculated using the formula F = G * (M1 * M2) / r^2, where M1 is the mass of the Earth, M2 is the mass of the Moon, and r is the distance between the centers of the Earth and the Moon.
Why is it important to consider the radius of the Earth when calculating gravitational force for objects on its surface?
-When calculating the gravitational force for objects on the Earth's surface, it's important to consider the Earth's radius because the force must be calculated from the center of the Earth to the object, not just the distance from the surface.
Outlines
🌍 Understanding Gravity
This paragraph introduces the concept of gravity using everyday examples, such as why objects remain on the Earth's surface. It discusses the famous story of Newton and the falling apple, which led him to ponder the force of gravity. The paragraph explains that gravity is not just about objects falling towards the Earth but also about the interaction between objects in space. It delves into Newton's law of universal gravitation, which states that the force of gravity is inversely proportional to the square of the distance between two objects and directly proportional to the product of their masses. The constant of universal gravitation (G) is introduced, with a value of 6.67 x 10^-11 N(m/kg)². The paragraph also touches on the idea that the gravitational force between the Earth and the Moon can be calculated using this law, taking into account the masses of the Earth and the Moon and the distance between their centers.
📉 Gravitational Acceleration
The second paragraph focuses on the concept of gravitational acceleration, which is the acceleration imparted to objects due to gravity. It clarifies the difference between gravitational force and gravitational acceleration, noting that the latter is commonly measured as 9.8 m/s² or 10 m/s². The paragraph summarizes the discussion on gravity from the previous section and sets the stage for further exploration of gravitational fields in upcoming videos. It concludes with a teaser for the next video, promising more information on the topic.
Mindmap
Keywords
💡Gravity
💡Newton
💡Mass
💡Distance
💡Universal Gravitation
💡Constant of Gravitation
💡Acceleration Due to Gravity
💡Earth's Mass
💡Moon
💡Cavendish
Highlights
Gravity is the force that keeps objects on the Earth's surface.
Without gravity, objects would not stay on the Earth's surface.
Gravity is a fundamental force that allows us to walk and sit comfortably.
The concept of gravity is often associated with Newton's apple story.
Newton pondered why an apple falls to the Earth but stars do not.
The force of gravity depends on the distance between two objects.
The gravitational force is inversely proportional to the square of the distance between objects.
The gravitational force is also directly proportional to the masses of the interacting objects.
Newton concluded that gravitational force is proportional to the product of the masses and inversely proportional to the square of the distance.
The gravitational constant, discovered by Cavendish, is approximately 6.67 x 10^-11 N(m/kg)².
The full equation for gravitational force is F = G * (M1 * M2) / r², where G is the gravitational constant.
The mass of the Earth is approximately 5.97 x 10^24 kg, which is much larger than the mass of a human.
The gravitational force between the Earth and the Moon can be calculated using the gravitational force equation.
The distance in the gravitational force equation should be measured from the centers of the two objects.
The acceleration due to gravity is approximately 9.8 m/s² or 10 m/s².
The difference between gravitational force and gravitational acceleration will be discussed in a future video.
Gravity is the attractive force between interacting objects.
The magnitude of gravity is calculated as F = G * (m1 * m2) / r².
Transcripts
dalam kehidupan sehari-hari setiap benda
bisa berada tetap di atas permukaan bumi
karena adanya gravitasi coba lo
berandai-andai deh kalau nggak ada
gravitasi Gimana caranya kita bisa
jalan-jalan gimana caranya kita bisa
duduk dengan tenang sambil nikmatin kopi
di Coffee Shop
tapi apa sih sebenarnya gaya gravitasi
itu kita akan bahas di video kali ini ya
[Musik]
cerita yang sering terdengar tentang
gravitasi tuh Newton Lagi duduk terus
kejatuhan apel itu nggak sepenuhnya
tepat Newton itu waktu itu berpikir
Kenapa apel jatuh ke bumi tapi bintang
gak jatuh ke bumi Coba deh lo ikutan
mikir kenapa apel bisa jatuh tapi
bintang gak jatuh ke bumi apa yang bisa
dibandingin antara apel dengan bintang
salah satu yang bisa dibandingin antara
kedua hal tadi adalah jaraknya apel bisa
jatuh ke bumi karena ada gaya tarik
gravitasi antara bumi dengan apel itu
Apakah bumi dengan bintang nggak ada
gaya tarik gravitasi
ada tapi sangat kecil karena jaraknya
jauh dari pengamatan ini Newton
menyimpulkan kalau misalnya gaya
gravitasi antara dua buah benda
berbanding terbalik dengan jarak antar
benda tersebut kuadrat berarti kalau
jaraknya makin jauh ya gaya gravitasinya
Makin kecil gitu kan Apakah cuma jarak
yang mempengaruhi gaya gravitasi gua ada
pertanyaan lagi kalau misalnya apel gue
taro dengan jarak yang sama antara apel
dengan permukaan bumi tadi ini jaraknya
antara gua dan apel nih ya kira-kira
apelnya akan geraknya kemana Apakah Dia
akan mendekat ke gue atau ke bumi
yups apelnya akan tertarik ke permukaan
bumi Loh kok gitu Padahal kan tadi
jaraknya sama
Berarti ada pengaruh lain untuk nilai
gaya gravitasi ini nilai itu dipengaruhi
oleh yang namanya masa masa antara benda
yang berinteraksi
Masa gue masa orang gitu ya itu ada di
range 10 pangkat 1 bisa 5 kali 10
pangkat 1 atau 50 itu bisa juga sampai
70 mungkin 100 kg sedangkan massa bumi
tahu nggak masa bumi Berapa masa bumi
itu 5,97 kali 10 pangkat 24 kg sangat
jauh lebih besar daripada massa orang
gitu kan berarti dari sini kan kita
lihat apel tertariknya ke bumi bukan ke
gue bukan ke orang dari sini Newton bisa
menyimpulkan kalau misalnya gaya
gravitasi itu berbanding lurus dengan
yang namanya massa antara kedua benda
yang berinteraksi makin besar massa dari
benda yang berinteraksi gaya
gravitasinya semakin besar
Newton nemuin persamaannya sampai sini
gaya gravitasi nilainya sebanding dengan
massa dari kedua benda yang berinteraksi
tapi berbanding terbalik dengan jarak
antar bendanya
tapi persamaan gaya gravitasi fullnya
tuh kayak gini f = g dikali M1 dikali M2
per r kuadrat G ini adalah konstanta
gravitasi umum yang ditemuin oleh
cavendice nanti lo akan bahas ini di
video berikutnya nilai dari konstanta
gravitasi umum adalah segini 6,67 x 10
pangkat minus 11 satuannya apa satuannya
Newton meter kuadrat per kg kuadrat
kalau contoh tadi gue bahasnya apel
dengan bumi sekarang gue mau bahas
contoh yang lain gua mau bahas contoh
bumi dengan bulan gaya gravitasi antara
bumi dengan bulan kita bisa cari pakai
persamaan ini ya f sama dengan G dikali
m1 m2 per r kuadrat M1 nya massa bumi M2
nya masa bulan r kuadrat ini r nya
adalah jarak antara bumi dan bulan lo
masih ingat kalau misalnya jarak antara
bumi dan bulan ini adalah jarak dari
ke pusat jarak dari pusat bumi ke pusat
bulan sehingga dengan perhitungan kita
dapat nilainya segini
untuk kasus apel di atas permukaan bumi
tadi kita kan tahu ketinggian apelnya
sebesar ini kan sebesar R ini kan Nah
ini sebenarnya belum sama jari-jari bumi
sedangkan kalau kita ngitung besar gaya
gravitasi antara bumi dengan objek lain
itu mesti dari pusat bumi jadi nanti
kalau mau Hitung gaya gravitasinya dalam
perhitungannya ini radiusnya jarak
antara bumi dan apelnya itu mesti lo
Tambahin sama radius bumi jadi nanti
persamaannya kayak gini
fyi di soal fisika itu kan sering banget
tuh disebut percepatan gravitasi
nilainya 9,8 m/s² atau 10 m/s² ini beda
ya sama gaya gravitasi yang kita bahas
di sini nilai itu sebenarnya adalah
nilai percepatan gravitasi atau medan
gravitasi yang akan kita bahas di video
berikutnya jadi gitu tentang gaya
gravitasi gaya gravitasi adalah gaya
tarik antara objek yang berinteraksi
gitu kan Nah besarnya itu adalah kayak
gini f sama dengan G dikali m1 m2 per r
kuadrat gitu aja untuk video kali ini
sampai jumpa di video berikutnya
[Musik]
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