1. Gravitation (Universal Force of Attraction)

Definition:

Gravitation is the universal force of attraction that acts between any two masses in the universe. It is described by Newton’s Law of Universal Gravitation and governs large-scale interactions like planetary motion.

Mathematical Representation:

Newton’s Law of Universal Gravitation states that the force between two masses is given by:

F = Gm₁m₂ / r²

Where:

• F = Gravitational force
• G = Universal gravitational constant
• m₁ and m₂ = Masses of two objects
• r = Distance between their centers

Examples of Gravitation:

• The Earth and the Moon attract each other due to gravitation.
• The Sun holds the planets in orbit due to its gravitational pull.
• Two objects placed near each other experience a weak attraction due to gravitation.

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2. Gravity (A Specific Case of Gravitation)

Definition:

Gravity is the force that pulls objects toward the center of a celestial body (like Earth). It is a special case of gravitation where one of the masses is a large celestial body.

Mathematical Representation:

• Weight of an object due to gravity:

W = mg

Where:

• W = weight (force due to gravity)
• m = mass of the object
• g = acceleration due to gravity (9.8 m/s² on Earth)
• Acceleration due to gravity on any planet:

g = GM/R²​

Where:

• g = acceleration due to gravity
• M = mass of the celestial body
• R = radius of the celestial body

Examples of Gravity:

• A ball falls to the ground when dropped.
• The Moon stays in orbit around Earth due to Earth’s gravity.
• An astronaut weighs less on the Moon because the Moon’s gravity is weaker than Earth’s.

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Key Differences Between Gravitation and Gravity

Feature	Gravitation	Gravity
Definition	The universal force of attraction between any two masses	The force exerted by a celestial body (like Earth) on objects near its surface
Scope	Acts between any two masses in the universe	Acts specifically between a planet (or celestial body) and nearby objects
Nature	Exists between any two objects with mass	Specific to Earth (or another planet/moon) pulling objects toward it
Force Equation	F = Gm1m2 / r2​​	W=mg
Effect on Objects	Keeps planets in orbit, holds galaxies together	Keeps objects on Earth’s surface, causes falling objects
Acceleration	Not directly defined	Acceleration due to gravity on Earth is 9.8 m/s29.8 \, m/s^29.8m/s2
Examples	The force between the Earth and the Sun	A person jumping and coming back to the ground

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FAQs on Gravitation and Gravity

Question 1: Is Gravitation a Repelling or Attractive Force?

Answer: The gravitational force is purely attractive in both theories, according to Newton’s General Theory of Relativity. However, the quantization of gravity demonstrates that gravitational force can also be repulsive.

Question 2: Why do we feel lighter on the equator than we do at the North Pole?

Answer: It’s because, in the equator, there’s more centrifugal force to counteract gravity’s effect. As a result, the equator has a lower overall weight than the poles.

Question 3: What are the methods used by spaceships to create artificial gravity?

Answer: Because of its spin around its axis, a starship can produce artificial gravity. A ship can also generate artificial gravity by constantly moving forward.

Question 4: What is free fall?

Answer: Any object that falls freely under the influence of Gravity is called the state of free fall.

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MCQs on Gravitation and Gravity

Question 1: What is the nature of gravitational force?

A. Always repulsive
B. Always attractive
C. Can be both attractive and repulsive
D. Neither attractive nor repulsive

Correct Answer: B. Always attractive
Explanation: According to Newton’s law of universal gravitation, gravity is always an attractive force.

Question 2: What is the value of acceleration due to gravity on Earth?

A. 7.8 m/s²
B. 8.9 m/s²
C. 9.8 m/s²
D. 10.8 m/s²

Correct Answer: C. 9.8 m/s²
Explanation: The acceleration due to gravity on Earth is approximately 9.8 m/s².

Question 3: What happens to the gravitational force if the distance between two masses is doubled?

A. It becomes half
B. It becomes one-fourth
C. It remains the same
D. It doubles

Correct Answer: B. It becomes one-fourth
Explanation: According to Newton’s law of gravitation, force is inversely proportional to the square of the distance between the objects.

Question 4: Where is the gravitational force zero on Earth?

A. At the equator
B. At the North Pole
C. At the center of the Earth
D. At sea level

Correct Answer: C. At the center of the Earth
Explanation: Gravitational force is zero at the center of the Earth because the mass distribution exerts equal force in all directions.

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Test Your Knowledge

body { margin: 0; padding: 0; font-family: Arial, sans-serif; } .quiz-container { width: 90%; max-width: 600px; margin: 20px auto; padding: 20px; border: 1px solid #ccc; border-radius: 10px; box-shadow: 0 0 10px rgba(0, 0, 0, 0.1); background: #f9f9f9; } .question { font-size: 18px; font-weight: bold; } .options { list-style: none; padding: 0; } .options li { margin: 10px 0; } button { display: block; margin: 20px auto; padding: 10px 20px; background: #28a745; color: white; border: none; cursor: pointer; border-radius: 5px; } button:hover { background: #218838; } .explanation { color: #007bff; margin-top: 10px; } .score { font-size: 20px; text-align: center; font-weight: bold; } const questions = [ { question: “What is gravity?”, options: [ “A force exerted by the Earth only”, “A force of attraction between any two masses”, “A repulsive force”, “Only the force that keeps planets in orbit” ], correct: 1, explanation: “Gravity is a specific case of gravitation, referring to the force exerted by Earth and other celestial bodies.” }, { question: “What is gravitation?”, options: [ “A force only present in space”, “A force of attraction between any two masses in the universe”, “A force only between planets”, “A force that works only on Earth” ], correct: 1, explanation: “Gravitation is a universal force that acts between any two masses, not just on Earth.” }, { question: “Which scientist formulated the law of universal gravitation?”, options: [“Albert Einstein”, “Galileo Galilei”, “Isaac Newton”, “Nikola Tesla”], correct: 2, explanation: “Isaac Newton formulated the law of universal gravitation, explaining how objects attract each other.” }, { question: “What does the law of universal gravitation state?”, options: [ “Gravity is only present on Earth”, “Every object with mass attracts every other object with mass”, “Gravitation does not work in space”, “Gravity is the same on all planets” ], correct: 1, explanation: “Newton’s law of universal gravitation states that all masses exert a force of attraction on each other.” }, { question: “Which of the following is an example of gravity?”, options: [ “The force between two stars”, “The attraction between the Sun and Earth”, “A ball falling to the ground”, “All of the above” ], correct: 3, explanation: “Gravity is a specific case of gravitation, such as the Earth pulling objects toward its surface.” } ]; let currentQuestion = 0; let score = 0; function loadQuestion() { const quizDiv = document.getElementById(“quiz”); const questionObj = questions[currentQuestion]; quizDiv.innerHTML = `

${questionObj.options.map((opt, index) => `
• ${opt}
`).join(”)}

`; } function checkAnswer(selectedIndex) { const explanationDiv = document.getElementById(“explanation”); const correctIndex = questions[currentQuestion].correct; if (selectedIndex === correctIndex) { score++; } explanationDiv.innerHTML = `

Correct Answer: ${questions[currentQuestion].options[correctIndex]}
${questions[currentQuestion].explanation}

`; } function nextQuestion() { if (currentQuestion < questions.length – 1) { currentQuestion++; loadQuestion(); } else { document.getElementById("quiz").innerHTML = "Quiz Completed!"; document.getElementById("score").innerHTML = `Your Score: ${score}/${questions.length}`; document.querySelector("button").style.display = "none"; } } loadQuestion();

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Conclusion:

• Gravitation is the general force that acts between any two masses.
• Gravity is a specific case of gravitation where a celestial body attracts objects toward it.
• Without gravitation, planets wouldn’t orbit the Sun, and without gravity, we wouldn’t stay on Earth! 🚀