NCERT books are considered the best source for clearing out the theoretical concepts and making the fundamentals strong. The questions and answers given in NCERT textbooks at the end of each chapter are quite important not only from examination point of view but also to get thorough understanding of the concepts in a better way. That is why students are recommended to follow NCERT books to score optimum marks in exams.
To help students access the accurate solutions to all NCERT questions, our experts have given a detailed explanation to all questions. All the answers have been framed in a very simple language to help students easily understand the concept and logic used.
Here you will get the NCERT Solutions for CBSE Class 9 Science chapter 10, Gravitation. All the solutions have been revised by subject experts to provide an error free study material to our students.
Main topics discussed in Class 9 Science chapter- Gravitation are:
- Gravitation and universal law of gravitation
- Importance of the universal law of gravitation
- Free fall
- Calculation of the value of g
- Motion of objects under the influence of gravitational force of the earth
- Mass of an object
- Weight of an object
- Weight of an object on the moon
- Thrust and pressure
- Pressure in fluids
- Why objects float or sink when placed on the surface of water?
- Archimedes’ principle
- Rrelative density.
Students may download all the NCERT Solutions for CBSE Class 9 Science chapter – Gravitation, in the form of PDF.
Some of the questions and their solutions from NCERT Solutions for Class 9: Gravitation, are as follows:
Q. What do you mean by free fall?
An object falling towards Earth freely due to the Earth’s gravitational pull alone is termed as an object under free fall.
Q. Why is it difficult to hold a school bag having a strap made of a thin and strong string?
It is difficult to hold a school bag having a strap made of a thin and strong string because the area under the strap is small. Hence large pressure is exerted by the strap on the fingers or shoulders. Due to the large pressure, the strap tends to cut the skin and hence pain is caused.
Q. Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?
Each object falls towards the earth with the acceleration, equal to acceleration due to gravity, which is constant (9.8 ms-2) and does not depend on the mass of the object. So, heavy object does not fall faster than the light object.
Q. What is the importance of universal law of gravitation?
The importance of universal law of gravitation can be understood from the following points:
a) All the planets revolve around the sun due to gravitational force between the sun and planets. Hence gravitational force is responsible for the existence of solar system.
b) Tides in oceans are formed due to the gravitational force between the moon and water in oceans.
c) The atmosphere of the earth is attached with it due to gravitational force of earth.
d) Artificial satellites revolve around the earth due to gravitational force of earth.
e) We can stand on the surface of earth due to gravitational force of earth.
Q. Why will a sheet of paper fall slower than one that is crumpled into a ball?
The sheet of paper falls slower than one that is crumpled into a ball because in first case the area of the sheet is more so it experiences large opposing force due to air. While the sheet crumpled into a ball experience less opposing force due to small area.
To get the complete solution click on the following link: