NCERT Solutions for Class 9 Science Chapter 9 Force and Laws of Motion
NCERT solutions for class 9 science chapter 9 Force and Laws of Motion: This chapter will help you to understand the concepts of force and laws of motion. Have you ever thought about what causes a body to move? How can we stop a moving body? How can we change the direction of a body? The answer to all the three questions is by applying a force. With the help of solutions for NCERT class 9 science chapter 9 Force and Laws of Motion, you will be able to understand the concepts of the chapter. Along with this chapter's solutions, you can also check NCERT solutions for other chapters and subjects. CBSE NCERT solutions for class 9 science chapter 9 Force and Laws of Motion, will help you to understand Newton's 3 laws of motion and another main topic inertia.
i) Newton's first law of motion:
Everybody continues its state of uniform motion along a straight line or state of rest unless acted by an external force. For example, if we hit a resting ball it will move and will not stop unless there is an external force. The external force acting here is friction which opposes the motion of the ball.
The momentum of a body is the product of its mass and velocity.
Newton's second law of motion: The rate of change of momentum of a body is directly proportional to the unbalanced force applied in the direction of the force.
If a body of mass m is moving with initial velocity u along a straight line. It is uniformly accelerated to a velocity v by applying a force for time t then, the rate of change of momentum = force applied. That is force applied
iii) Newton's third law of motion
Newton's third law of motion states that every force has equal and opposite reactions. For example, when a bullet is fired from a gun, the gun exerts a forward force on the bullet and the bullet exerts a backward force on the gun. That is why the gun moves back (recoil of the gun) when fired.
iv) Interia: The inertial of an object is its natural tendency to continue its state of rest or motion. Mass is the measure of the inertia of an object. For example, when a moving bus applies brake people in the bus moves forward, this is due to the inertia of motion
The main topics of NCERT Solutions for Class 9 Science Chapter 9 Force and Laws of Motion are:
9.1 Balanced and Unbalanced Forces
9.2 First Law of Motion
9.3 Inertia and Mass
9.4 Second Law of Motion
9.5 Third Law of Motion
9.6 Conservation of Momentum
The answer given herein for the questions mentioned at the end of the chapter will help you to revise the chapter. As per the CBSE syllabus & exam pattern, the chapter 9 Force and Laws of Motion is a part of 3rd unit, Motion, Force and work carry weightage of 27 marks in the final exam of class 9.