Welcome to StudyMats. This comprehensive educational guide for Class 9 Science Sample Paper | Chapter: Gravitation | Bilingual is prepared to assist students in preparing effectively for their school, board, and competitive examinations. All questions, exercise solutions, and concept notes strictly adhere to the latest NCERT curriculum and CBSE guidelines.
Class 9 Science Sample Paper | Chapter: Gravitation
Gravitation – Solved Worksheet
Section A: MCQs (1 Mark Each)
Q1. The value of Universal Gravitational Constant (G) was first determined by:
सार्वत्रिक गुरुत्वाकर्षण नियतांक (G) का मान सबसे पहले किसके द्वारा निर्धारित किया गया था?
(a) Isaac Newton (b) Henry Cavendish (c) Johannes Kepler (d) Galileo Galilei
Q2. The value of acceleration due to gravity (g) is:
गुरुत्वीय त्वरण (g) का मान होता है:
(a) Maximum at poles (b) Maximum at equator (c) Same everywhere (d) Zero at poles
Q3. Two objects of different masses falling freely near the surface of the moon would:
चंद्रमा की सतह के पास स्वतंत्र रूप से गिरने वाली विभिन्न द्रव्यमानों की दो वस्तुओं में क्या होगा?
(a) Have different accelerations (b) Have same velocities at any instant (c) Experience same forces (d) Undergo change in inertia
Q4. The weight of an object on the Moon is _____ of its weight on the Earth.
चंद्रमा पर किसी वस्तु का भार पृथ्वी पर उसके भार का _____ होता है।
(a) 1/2 (b) 1/4 (c) 1/6 (d) 1/10
Section B: Short Answer (2 Marks)
Q5. State the Universal Law of Gravitation.
गुरुत्वाकर्षण का सार्वत्रिक नियम बताइए।
Q6. Differentiate between Mass and Weight.
द्रव्यमान और भार के बीच अंतर स्पष्ट करें।
Q7. What is Free Fall?
मुक्त पतन (Free Fall) क्या है?
Section C: Numerical & Long Answer (3-4 Marks)
Q8. An object weighs 10 N when measured on the surface of the earth. What would be its weight when measured on the surface of the moon?
पृथ्वी की सतह पर मापने पर एक वस्तु का भार 10 N आता है। चंद्रमा की सतह पर मापने पर इसका भार क्या होगा?
Q9. A ball is thrown vertically upwards with a velocity of 49 m/s. Calculate the maximum height to which it rises. (Take g = 9.8 m/s²)
एक गेंद को 49 m/s के वेग से लंबवत ऊपर की ओर फेंका जाता है। उसके द्वारा प्राप्त अधिकतम ऊंचाई की गणना करें।
Q10. Relative density of silver is 10.8. The density of water is 10³ kg/m³. What is the density of silver in SI unit?
चांदी का आपेक्षिक घनत्व 10.8 है। पानी का घनत्व 10³ kg/m³ है। SI मात्रक में चांदी का घनत्व क्या होगा?
Detailed Solutions (विस्तृत समाधान)
Ans 1: (b) Henry Cavendish
Newton gave the law, but Cavendish determined the value of G using a sensitive balance.
Ans 2: (a) Maximum at poles
Since the Earth is flattened at the poles, the radius is smaller, making 'g' stronger at poles than at the equator.
Ans 3: (b) Have same velocities at any instant
Acceleration due to gravity is independent of the mass of the falling object.
Ans 4: (c) 1/6
Moon's gravity is approximately 1/6th of Earth's gravity.
Ans 5: English: Every object in the universe attracts every other object with a force proportional to the product of their masses and inversely proportional to the square of the distance between them.
Hindi: ब्रह्मांड का प्रत्येक पिंड प्रत्येक अन्य पिंड को एक बल से आकर्षित करता है जो उनके द्रव्यमानों के गुणनफल के समानुपाती और उनके बीच की दूरी के वर्ग के व्युत्क्रमानुपाती होता है।
Ans 6: Mass (द्रव्यमान): Amount of matter, constant everywhere, SI unit kg.
Weight (भार): Force of gravity, changes with location (W=mg), SI unit Newton (N).
Ans 7: English: When an object falls towards the earth under the sole influence of gravity, it is called free fall.
Hindi: जब कोई वस्तु केवल गुरुत्वाकर्षण बल के प्रभाव में पृथ्वी की ओर गिरती है, तो इसे मुक्त पतन कहते हैं।
Ans 8: Weight on Moon = 1/6 × Weight on Earth
Wm = 1/6 × 10 N = 1.67 N.
Ans 9: u = 49 m/s, v = 0 (at max height), g = -9.8 m/s² (upward motion).
Using v² = u² + 2gh:
0 = (49)² + 2(-9.8)H
19.6H = 2401 => H = 2401 / 19.6 = 122.5 m.
Ans 10: Density of silver = Relative Density × Density of Water
Density = 10.8 × 10³ kg/m³ = 10800 kg/m³.
💡 Important Exam & Study Tips
- Master NCERT Fundamentals: Ensure thorough familiarity with standard textbook definitions, formulas, and in-text examples before solving advanced problems.
- Step-by-Step Presentation: In board examinations, neat presentation, correct formula application, and labeled steps earn maximum step-marking.
- Practice Under Timed Conditions: Regular practice with previous years' question papers (PYQs) builds exam speed and accuracy.
📚 Related Study Materials on StudyMats
Access more chapter-wise notes and practice papers:
- StudyMats Home — Complete Educational Study Material
- Acceleration due to Gravity Study Notes & Question Papers
- Class 9 Physics Study Notes & Question Papers
- Class 9 Science Study Notes & Question Papers
- Free Fall Questions Study Notes & Question Papers
❓ Frequently Asked Questions (FAQs)
Q1: Are these solutions aligned with the latest rationalized syllabus?
Yes, all study notes and practice questions on StudyMats strictly follow the updated NCERT textbook pattern and CBSE assessment guidelines.
Q2: How can I prepare this chapter for highest marks?
Review the theory thoroughly, solve all textbook exercise questions, and repeatedly practice the high-frequency questions provided in this guide.