1 give reasons
A) Cinema halls and auditoriums are carpeted and their walls are coated with rough material
b) Echoes are not formed in our classrooms
a) Cinema halls and audutoriums are carpeted and the walls are made of rought material. It is because these materials absorb the sound and do not allow them from going out of as, some times the sound can be a trouble to the people.
b) An echo is produced when the sound waves bounce back and forth on an even surface. Echoes are not produced in a classroom because of the furniture, people and other uneven things it. These things make the surface area in the room uneven. If the classroom would be empty the sound would echo because of the even surface in it.