Sound needs a medium to travel: The substance through which sound travels is called a medium. It can be solid, liquid or a gas. Sound wave is a mechanical wave and requires a material medium like air, water, steel, etc., for its propagation. Sound wave cannot travel in vaccum.This can be proved by bell jar activity.
Activity:
1. An electric bell is suspended inside a bell jar by its leads.
2. A pipe through the cork leads out to vaccum pump(pump which draws the air out of a vessel).
3. The bell is connected to a battery through the key.
4. The bell is started by closing the key. Initailly when jar has normal air inside it, sound waves produced by the ringing bell heard outside the jar.
5. The vaccum pump is started and the air from inside the jar is gradually drawn out. With decreased air inside the jar, sound heard becomes weaker and weaker but the strikes can still be seen to be moving, after sometimes no sound is heard. This suggests that sound needs material medium to travel.
Sound cannot travel in __________________. | |||
Right Option : D | |||
View Explanation |
A bomb explodes on the moon. How long will it take sound to reach the reath ? | |||
Right Option : D | |||
View Explanation |
A wave travels through a medium with a speed of 340 m/s. If the frequency of the wave is doubled, what happens to the wave speed ? | |||
Right Option : B | |||
View Explanation |
My experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
My experience with Abhyas is very good. I have learnt many things here like vedic maths and reasoning also. Teachers here first take our doubts and then there are assignments to verify our weak points.
It was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.
Abhyas is a complete education Institute. Here extreme care is taken by teacher with the help of regular exam. Extra classes also conducted by the institute, if the student is weak.
It has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
Being a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
A marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
One of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
About Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
It was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.