9th Class Physics Chapter 5 Notes

Complete Notes of 9th Class Physics Chapter 5 Notes Gravitation Notes of 9th Class Physics English Medium written by Professor Tayyab Shahzad. These computerized notes are very helpful in the preparation of Gravitation Notes for students of the 9th Class Physics Chapter 5 Notes these are according to the paper patterns of all Punjab boards.

• Here are the detailed Class 9 Physics Notes Chapter 5 to help you prepare for your exams.
• Gravitation Exercise Multiple Choice Questions ( MCQs ) with Correct Answers
• Gravitation Exercise Short Questions with Answers
• What is meant by the force of gravitation?
• What is a field force?
• Why earlier scientists could not go about the gravitational force?
• Explain, what is meant by gravitational field strength. 
• Explain the law of gravitation.
• Why law of gravitation is important to us?
• How the mass of the earth can be determined?
• Why does the value of g vary from place to place?
• You can also download the Class 9 Physics Chapter 5 Notes pdf for free.
• Can you determine the mass of our moon? If yes, then what do you need to know?
• Explain how the value of g varies with altitude. 
• How does Newton’s law of gravitation help in understanding the motion of satellites?
• What are artificial satellites? 
• Why communication satellites are stationed at geostationary orbits?
• On what factors the orbital speed of a satellite depends? 
• Important Values and Important Formulas
• Gravitation Exercise Numericals with Solutions
• Newton's law of gravitation. 
• Explain that the gravitational forces are consistent with Newton's third law.
• Explain gravitational field as an example of field of force.
• Define weight (as the force on an object due to a gravitational field.)
• Calculate the mass of Earth by using law of gravitation.
• Solve problems using Newton's law of gravitation.
• Explain that value of g decreases with altitude from the surface of Earth.
• Discuss the importance of Newton's law of gravitation in understanding the motion of satellites.
• If you're looking for comprehensive Physics Notes for Class 9th Chapter 5, you've come to the right place.
• The first man who came up with the idea of gravitywas Isaac Newton. It was an evening of 1665 when he was trying to solve the mystery why planets revolve around the Sun. Suddenly an apple fell from the tree under which he was sitting. The idea of gravity flashed in his mind. He discovered not only the cause of falling apple but also the cause that makes the planets to revolve around the Sun and the moon around the Earth. 
• The force of gravitation class 9: On the basis of his observations, Newton concluded that the force which causes an apple to fall on the Earth and the force which keeps the moon in its orbit are of the same nature. He further concluded that there exists a force due to which everybody of the universe attracts every other body. He named this force the force of gravitation.
• Law of Gravitation class 9: According to Newton's law of universal gravitation:
• Everybody in the universe attracts every other body with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.
• Consider two bodies of masses m1 and m2. The 1 distance between the centres of masses is d. Two masses attract each other with a gravitational force of equal magnitude.  According to the law of gravitation, the According to the law of gravitation, the gravitational force of attraction F with which the two masses m and m separated by a distance d attract each other is given by: F = G m1m2/ d^2 
• Here G is the proportionality constant. It is called the universal constant of gravitation. Its value is same everywhere. In SI units its value is 6.673x10^-11 Nm^2 kg^-2. Due to small value of G, the gravitational force of attraction between objects around us is very small and we do not feel it. Since the mass of Earth is very large, it attracts nearby objects with a significant force.