Extra Questions for Class 9 Science Chapter 10 Gravitation
Here we are providing extra questions for class 9 science chapter 10 gravitation. Various type of questions are provided. These includes very short answer type questions, short answer type questions and long answer type questions as well. These questions are important for exam as well. You will be able to score more in your exams by practicing these questions.
Very Short Answer Type Question (VSA)
Q.1. State a relation between thrust and pressure.
Q.2. State any one phenomena related to the Universal Law of Gravitation.
Q.3. State Archimedes principle.
Q.4. State universal law of gravitation.
Q.5. State two factors in which the gravitational force between two objects depends.
Q.6. What is the gravitational force between the Earth and a body called?
Q.7. Why are sleepers used below the rails?
Q.8. The gravitational force between two objects is F. How will the force change when the distance between them is reduced to 1/4th?
Q.9. What is meant by buoyant force?
Q.10. A body of weight 20 N floats half submerged in a liquid. What is the buoyant force on the body?
Q.11. The G. Force between two objects is F. How will this force change when the distance between them is reduced to half?
Q.12. Define mass of an object?
Q.13. Why is G called the Universal Constant?
Q.14. What is meant by free fall?
Q.15. The Earth is acted upon by the gravitational force of attraction due to the Sun. Then why does the Earth not fall towards the Sun?
Q.16. Two objects of masses M1 and M2 are dropped in vacuum from a height above the surface of Earth (M1 is grater than M2). Which one will reach the ground first and why?
Q.17. An object of mass 2 kg falls with an acceleration of 9.8 m/s2 towards the ground. With what acceleration will an object of mass 4 kg fall?
Q.18. Write the units of ‘g’ and ‘G’?
Q.19. Mass of an object is 10 kg. What is its weight on the Earth? (g = 9.8 m/s2)
Short Answer Type Questions
Q.1. What is the source of centripetal force that a planet requires to revolve around the Sun? On what factors does that force depend?
Q.2. On the earth, a stone is thrown from a height in a direction parallel to the earth’s surface while another stone is simultaneously dropped from the same height. Which stone would reach the ground first and why?
Q.3. Suppose gravity of earth suddenly becomes zero, then in which direction will the moon begin to move if no other celestial body affects it?
Q.4. Identical packets are dropped from two aeroplanes, one above the equator and the other above the north pole, both at height h. Assuming all conditions are identical, will those packets take same time to reach the surface of earth. Justify your answer.
Q.5. The weight of any person on the moon is about 1/6 times that on the earth. He can lift a mass of 15 kg on the earth. What will be the maximum mass, which can be lifted by the same force applied by the person on the moon?
Q.6. Calculate the average density of the earth in terms of g, G and R.
Q.7. The earth is acted upon by gravitation of Sun, even though it does not fall into the Sun. Why?
Q.8. Calculate the density of Earth from Newton’s law of gravitation.
Q.9. A body weighs more at poles than at the equator of earth. Why?
Q.10. Two particles of equal mass (m) move in a circle of radius (r) under the action of their mutual gravitational attraction. Find the speed of each particle.
Long Answer Type Questions
Q.1. How does the weight of an object vary with respect to mass and radius of the earth. In a hypothetical case, if the diameter of the earth becomes half of its present value and its mass becomes four times of its present value, then how would the weight of any object on the surface of the earth be affected?
Q.2. How does the force of attraction between the two bodies depend upon their masses and distance between them? A student thought that two bricks tied together would fall faster than a single one under the action of gravity. Do you agree with his hypothesis or not? Comment.
Q.3. Two objects of masses m1 and m2 having the same size are dropped simultaneously from heights h1 and h2 respectively. Find out the ratio of time they would take in reaching the ground. Will this ratio remain the same if (i) one of the objects is hollow and the other one is solid and (ii) both of them are hollow, size remaining the same in each case. Give reason.
You may also like:
Extra questions for other chapters of class 9 science is given below.
Chapter 3 Atoms and Molecules
Chapter 4 Structure of Atom
Chapter 10 Gravitation
Chapter 11 Work and Energy
Chapter 13 Why Do We Fall Ill?