The acceleration due to gravity changes with distance from Earth’s center.
Develop multiple-choice questions (MCQs) for Chapter 7, “Gravitation,” from the NCERT Class 11 Physics textbook, following the CBSE syllabus for 2024β2025. The questions should encompass important concepts like the universal law of gravitation, gravitational force, acceleration due to gravity and its variations with altitude and depth. Include topics such as orbital motion, escape velocity and Kepler’s laws of planetary motion. Each MCQ should have four options with one correct answer, aiming to test studentsβ conceptual understanding, analytical thinking and ability to apply gravitational principles. Ensure the questions are concise, accurate and tailored for effective exam preparation.
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The acceleration due to gravity (g) decreases with an increase in altitude because the distance from the center of the Earth increases. The gravitational force follows the inverse square law.
The formula to calculate the value of g at a height (h) above the Earth’s surface is:
gβ = gβ * (R / (R + h))Β²
Where:
gβ = acceleration due to gravity at height h
gβ = acceleration due to gravity on Earth’s surface (approximately 9.8 m/sΒ²)
R = radius of the Earth (approximately 6,371 km or 6.371 Γ 10^6 m)
h = height above Earth’s surface
### Key Points:
1. At higher altitudes, the distance (R + h) from the Earth’s center increases, resulting in a smaller value of gβ.
2. The decrease in g is noticeable at significant altitudes, such as those of satellites or mountain peaks, but negligible for everyday heights.
3. At very high altitudes, where h is comparable to or larger than R, the effect becomes more pronounced.
### Example:
For an altitude of 100 km (h = 100,000 m):
gβ = 9.8 * (6.371 Γ 10^6 / (6.371 Γ 10^6 + 100,000))Β²
After calculation, gβ is slightly less than 9.8 m/sΒ², illustrating the decrease in g with altitude.
This question related to Chapter 7 physics Class 11th NCERT. From the Chapter 7. Gravitation. Give answer according to your understanding.
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https://www.tiwariacademy.com/ncert-solutions/class-11/physics/chapter-7/