Question

II. Fill in the blanks.
1. Sound is a
wave and needs a
material medium to travel.
2. Number of vibrations produced in one second
3. The velocity of sound in solid is
than the velocity of sound in air.
4. Vibration of object produces _*​

Answer 1

vibration of objects produces waves

Answer 2

Answer:

1. propagations 2. 20,000 3. solids