Tuning fork experiment.
class-9 with full procedure???
Answers
Experiment 1:
Resonance with tuning fork .
Explanation:
Mount two identical tuning forks A and B of the same frequency on two separate sound boxes such that their open ends face each other as shown in figure 7.8 . When the prong of one of the tuning forks say , A is struck on a rubber pad , it starts vibrating . On putting the tuning fork A on its sound box , we find that the other tuning fork B also starts vibrating and a loud sound is heard .
Reason:-
The vibrating tuning fork A produces the forced vibrations in the air column of its sound box. These vibrations are of large amplitude because of large surface area of air in the sound box . They are communicated to the sound box of the fork B. The air column of B starts vibrating with the frequency of fork A . Since the frequency of these vibrations is same as the natural frequency of the fork B , the fork B picks up these vibrations and starts vibrating under resonance. Thus the two sound boxes help in communicating the vibrations and in increasing the amplitude of vibrations.
Experiment 2:
Take a tuning fork and set it vibrating by striking its prong on a rubber pad. Bring it near your ear.
Do you hear any sound?
Touch one of the prongs of the vibrating tuning fork with your finger and share your experience with your friends.
Now, suspend a table tennis ball or a small plastic ball by a thread from a support [Take a big needle and a thread, put a knot at one end of the thread, and then with the help of the needle pass the thread through the ball]. Touch the ball gently with the prong of a vibrating tuning fork (Fig. 1)
Observations:
In the above activity we have produced sound by striking the tuning fork. We can also produce sound by plucking, scratching, rubbing, blowing or shaking different objects. As per the above activities what do we do to the objects? We set the objects vibrating and produce sound. Vibration means a kind of rapid to and fro motion of an object. The sound of the human voice is produced due to vibrations in the vocal cords. When a bird flaps its wings, do you hear any sound? Think how the buzzing sound accompanying a bee is produced. A stretched rubber band when plucked vibrates and produces sound. If you have never done this, then do it and observe the vibration of the stretched rubber band
hope it helps!!!!
