Question

-its position
6. When unbalanced forces acts on the object
a. will change
b. does not change
c. will never change
d. None of the above
II. Fill in the blanks
7. In a school, Mani played a football match. He kicked the ball into the goal post . Football
kicked by Mani is an example of
force
8. Electrostatic force is an example of
force.
9. The parading of soldiers in a parade is
motion
10. The earth moves around the sun is an example of
motion
11. A spin bowler delivers a ball is an example of
III. Answer briefly​

Answer 1

Answer:

person_pin CBSE library_books MECHANICS class CLASS 9 favorite 51.4 K

TABLE OF CONTENT

TABLE OF CONTENT

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

WHAT YOU HAVE LEARNT

EXERCISE

ADDITIONAL EXERCISES

In the previous chapter, we described the motion of an object along a straight line in terms of its position, velocity and acceleration. We saw that such a motion can be uniform or non-uniform. We have not yet discovered what causes the motion. Why does the speed of an object change with time? Do all motions require a cause? If so, what is the nature of this cause? In this chapter we shall make an attempt to quench all such curiosities.

For many centuries, the problem of motion and its causes had puzzled scientists and philosophers. A ball on the ground, when given a small hit, does not move forever. Such observations suggest that rest is the “natural state” of an object. This remained the belief until Galileo Galilei and Isaac Newton developed an entirely different approach to understand motion.

Figure-1 Pushing, pulling, or hitting objects change their state of motion.

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