9th Class Physics Chapter 3 Notes

Complete Notes of 9th Class Physics Chapter 3 Notes Dynamics Notes of 9th Class Physics English Medium written by Professor Tayyab Shahzad. These computerized notes are very helpful in the preparation of Dynamics Notes for students of the 9th Class Physics Chapter 3 Notes these are according to the paper patterns of all Punjab boards.

• Here are the detailed Class 9 physics notes chapter 3 to help you prepare for your exams.
• Dynamics Exercise Multiple Choice Questions ( MCQs ) with correct Answers
• Dynamics Exercise Short Questions with Answers
• Define the following terms: (a) Inertia (b) Momentum (c) Force (d) Force of friction (e) Centripetal force
• What is the law of inertia?
• What is the difference between? (a) Mass and weight. (b) Action and reaction. (c) Sliding friction and rolling friction.
• Why is it dangerous to travel on the roof of a bus? 
• How can you relate a force with the change of momentum of a body?
• Why does a passenger move outward when a bus takes a turn?
• What will be the tension in a rope that is pulled from its ends by two opposite forces 100N each?
• Action and reaction are always equal and opposite. Then how does a body move?
• What is the law of conservation of momentum?
• When a gun is fired, it recoils. Why?
• You can also download the class 9 physics chapter 3 notes pdf for free.
• Why is the law of conservation of momentum important?
• Describe two situations in which force of friction is needed.
• Describe ways to reduce friction.
• How does oiling the moving parts of a machine lowers friction?
• Why roiling friction is less than sliding friction?
• What you know about the following: (a) Tension in a string Limiting force of friction (a) Braking force (b) Skidding of vehicles (c) Seatbelts (d) Banking of roads (e) Cream separator
• If you're looking for comprehensive physics notes for class 9th chapter 3, you've come to the right place.
• Important Conversion and Important Formulas
• Dynamics Exercise Numericals with Solutions
• In kinematics, we have studied the changes in motion only. Our understanding about the changes in motion is of little value without knowing its causes. The branch of mechanics that deals with the study of motion of an object and the cause of its motion is called dynamics. In this unit, we shall study momentum and investigate what causes a change in the motion of a body and what role the mass of a body plays in its motion. This inquiry leads us to the concept of force. We shall also study the laws of motion and their applications.
• Force and laws of motion class 9th: FORCE, INERTIA AND MOMENTUM: Newton's laws of motion are of fundamental importance in understanding the causes of motion of a body. Before we discuss these laws, it is appropriate to understand various terms such as force, inertia and momentum.
• What happens when you press a balloon? You can cut an apple with a knife by pushing it sharp edge into the apple. Thus a force can also change the shape or size of a body on which it acts.
• "Inertia of a body is its property due to which it resists any change in its state of rest or motion".
• MOMENTUM: A bullet has a very small inertia due to its small mass. But why does its impact is so strong when it is fired from the gun? On the other hand, the impact of a loaded truck on a body coming its way is very large even if the truck is moving slowly. To explain such situation, we define a new physical quantity called momentum. 
• "Momentum of a body is the quantity of motion it possesses due to its mass and velocity". 
• The momentum P of a body is given by the product of its mass m and velocity v. Thus     P = mV  Momentum is a vector qnantity. Its SI unit is Kgms-1.
• Newton's laws of motion class 9: Newton was the first to formulate the laws of motion known as Newton's laws of motion.
• First law of motion class 9 notes: First law of motion deals with bodies which are either at rest or moving with uniform speed in a straight line. According to Newton's first law of motion, a body at rest remains at rest provided no net force acts on it. This part of the law is true as we observe that objects do not move by themselves unless someone moves them. For example, a book lying on a table remains at rest as long as no net force acts on it.
• "A body continues its state of rest or of uniform motion in a straight line provided no net force acts on it".