PhysicsKund Physics class 9 to 12 NCERT, JEE - NEET

NCERT Solutions for class 9 Science chapter 8 Forces and Laws of Motion is prepared and uploaded for reference by academic team of expert members. Get solutions of all chapters of NCERT class 9 Science. use as a reference of the following NCERT solutions of chapter 8 prepared. Read the theory of chapter-8 Forces and Laws of Motion while before going to exam. Page no :  91 Question 1 to 4 :  Question 1. Which of the following has more inertia : (a) a rubber ball and a stone of the same size? (b) a bicycle and a train? (c) a five rupees coin and a one-rupee coin? Solution : (a) a stone of the same size will have more inertia than a rubber ball. (b) A train will have more inertia than a bicycle. (c) A five rupees coin will have more inertia than a one-rupee coin. Question 2. In the following example, try to identify the number of times the velocity of the ball changes: “A football player kicks a football to another player of his team who kicks the football towards the goal. The ...

NOTES CBSE Class 9 Science Chapter 8 Force and Law of motion  Definition of Force :  Force enables us to do any work.  To do anything, either we pull or push the object that produces an acceleration in the object on which it acts Therefore,  pull or push is called force . S.I. unit of force is Newton. Example:  1. To open a door, either we push or pull it.  2. A drawer is pulled to open and pushed to close. Effect of Force :   (i) Force can make a stationary (Rest) body in motion. For example, a football can be set to move by kicking it, i.e., by applying a force. (ii) Force can stop a moving body.  For example, by applying brakes, a running cycle or a running vehicle can be stopped. (iii) Force can change the direction of a moving object.  For example, by applying force, i.e., by moving handle, the direction of a running bicycle can be changed. Similarly by moving steering, the direction of a running vehicle is changed. (iv) Force can change...

Newton studied the ideas of Galileo and gave the three laws of motion. These Laws are known as Newton's laws of motion. Newton's First Law of Motion (Law of Inertia): Any object remains in the state of rest or in uniform motion along a straight line, until it is compelled to change the state by applying external force. Explanation: If any object is in the state of rest, then it will remain in rest until a external force is applied to change its state. Similarly, an object will remain in motion until any external force is applied over it to change its state. This means all objects resist to in changing their state. The state of any object can be changed by applying external forces only. Example : a) A person standing in a bus falls backward when bus starts moving suddenly. This happens because the person and bus both are in rest while bus is not moving, but as the bus starts moving, the legs of the person start moving along with bus but rest portion of his body has the tendency ...

What is Force , it's Effect , Type of force : Balance and Unbalance force  Definition of Force :  Force enables us to do any work.  To do anything, either we pull or push the object that produces an acceleration in the object on which it acts Therefore, pull or push is called force . S.I. unit of force is Newton. Example:  1. To open a door, either we push or pull it.  2. A drawer is pulled to open and pushed to close. Effect of Force :   (i) Force can make a stationary (Rest) body in motion. For example, a football can be set to move by kicking it, i.e., by applying a force. (ii) Force can stop a moving body.  For example, by applying brakes, a running cycle or a running vehicle can be stopped. (iii) Force can change the direction of a moving object.  For example, by applying force, i.e., by moving handle, the direction of a running bicycle can be changed. Similarly by moving steering, the direction of a running vehicle is changed. (iv) Force can...