## NCERT Books for Class 9 Science - Force and Laws of Motion - Free PDF Download

NCERT Books for Class 9 Science Chapter 9

## FAQs on NCERT Books for Class 9 Science Chapter 9

**1. What are the three Laws of motion mentioned in NCERT Books for Class 9 chapter 9 Forces and Laws of Motion?**

The three Laws of motion discussed in this chapter are the most important sections and are often asked in the exams. They are the following:

First Law of Motion: An object continues to be in the state of rest or of uniform motion along the straight line unless acted upon by an unbalanced external force.

Second Law of Motion: The rate of change of momentum of an object is proportional to the applied unbalanced force and the change takes place in the direction of the force.

Third Law of Motion: To every action, there is an equal and opposite reaction.

**2. How do we derive the mathematical formulation of the Second Law of Motion?**

The Second Law of Motion states that the rate of change of momentum of an object is proportional to the applied unbalanced force in the direction of the force. Suppose an object of mass *m* is moving in a straight line with an initial velocity *u *and is uniformly accelerated at a velocity* v *in time t with a constant force F. We know that acceleration a= (v-u)/t. Hence the formula for this motion is F=ma. The S.I of force is kg m/s^{2} or N.

**3. Is the NCERT Class 9 chapter 9 Forces and Laws of Motion difficult?**

NCERT Class 9 chapter 9 Forces and Laws of Motion is not a very difficult chapter but is tricky to understand depending on the questions asked. Students must be very clear with the concepts involving the laws since most of the questions, be it short answer types or Multiple Choice Questions or numericals, will be worded in a manner such that students might get confused. Hence, this chapter has to be revised, practiced and prioritized to score well in the exam.

**4. Can we download the NCERT Class 9 chapter 9 Forces and Laws of Motion online?**

NCERT Books Free Download for Class 9 Science Chapter 9 - Force and Laws of Motion are available online on Vedantu. Vedantu has been helping students bring out their best abilities and capabilities by preparing new sample papers and updating them with time. Study materials have also been uploaded for students to download at any time which can be used for revision ahead of the test. Students need not search online for too many resources since they can find all of it in one!

**5. Are there numericals given in NCERT Class 9 chapter 9 Forces and Laws of Motion?**

Yes, numericals are mainly based on the three Laws of Motion, especially in the case of the Second Law of Motion. These numericals only test the basic knowledge and understanding of the concepts of the students and are given in the form of exercises both in between as well as after the chapters. The numericals are not tough but tricky so that students can adapt themselves to the different levels of difficulty which will boost their performance in the exams and also prepare them for the worst.