9th Standard Syllabus & Materials
9th Standard
TN 9th Tamil உள்ளத்தின் சீர் -கற்கண்டு (இலக்கணம்) - தொடர் இலக்கணம், ஆகுபெயர் Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil உள்ளத்தின் சீர் -விரிவானம் (துணைப்பாடம்) - தாய்மைக்கு வறட்சி இல்லை! Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil உள்ளத்தின் சீர் -கவிதை பேழை (செய்யுள்) - மார்கழி பெருவிழா Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil உயிருக்கு வேர்-இலக்கணம் - பகுபத உறுப்பிலக்கணம் Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil அமுதென்று பேர் - இலக்கணம்-எழுத்து -அளபெடை Important Questions And Answers Study Material - QB365 Set A
NEW9th Standard
TN 9th Tamil அமுதென்று பேர்-துணைப்பாடம் - ஆறாம்திணை Important Questions And Answers Study Material - QB365 Set A

Published on: 16/06/2021
QB365 provides detailed and simple solution for every Book back Questions in class 9 Science Subject. It will helps to get more idea about question pattern in every book back questions with solution.
Download Tamil Nadu 9th Standard Science question papers, model tests, one-mark questions, important questions, and public exam papers in PDF format. Free study materials and answer keys for TN State Board students.
Questions + Answers key
Take MCQ Science Test1.
You and your friend are on the moon. Will you be able to hear any sound produced by your friend?
2.
What is meant by supersonic speed?
3.
Can sound travel through vacuum?
4.
Through which medium sound travels faster, iron or water? Give reason.
5.
A stone is dropped from the top of a tower 750 m high into a pond of water at the base of the tower. Calculate the number of seconds for the splash to be heard?
(Given g = 10 m s–2 and speed of sound = 340 m s–1)
1.
No, he will not be able to hear the sound produced by his friend.
2.
When an object travels at a speed higher than that of sound in air, it produces shock waves. These shock waves carry a large amount of energy. The air pressure variations associated with this type of shock waves produce a very sharp and loud sound called sonic bloom or supersonic speed.
3.
No, sound cannot travel through vacuum.
Because, sound can travel only when there are particles, which can be compressed and rarefied in the medium.
4.
Reason: In solid, particles are packed closer than in liquid and gaseous. So sound waves travel easily in solid. Sound travel faster in iron.
5.
Velocity of sound = 340 ms-1
Height of tower = 750 m
Total distance travelled = 2 x 750: 1500 m
\(Valocity=\frac {distance}{time}\)
\(340=\frac {1500}{time}\)
\(time=\frac {1500}{340}=4.4s\)
After 4.4 s, the splash is heard.
9th Standard Syllabus & Materials
9th Standard
TN 9th Tamil உள்ளத்தின் சீர் - திருக்குறள் Important Questions And Answers Study Material - QB365 Set A
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TN 9th Tamil உள்ளத்தின் சீர் - மணிமேகலை Important Questions And Answers Study Material - QB365 Set A
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TN 9th Tamil உள்ளத்தின் சீர் - ஏறு தழுவுதல் Important Questions And Answers Study Material - QB365 Set A
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TN 9th Tamil உயிருக்கு வேர் - தண்ணீர் Important Questions And Answers Study Material - QB365 Set A
Tamilnadu Stateboard 9th Standard Subjects
Tamilnadu Stateboard Standards