Answer:
An echo is formed as a result of reflection of the original sound which returns to the listener. You might have experienced Echo in an EMPTY ROOM but no echo is produced after the room is occupied. To avoid echo from being produced the echo has to be absorbed. Echo in a cinema theatre is absorbed by the WALLS of the theatre.
They are not plain. The walls are corrugated or shaped to form tiny holes or empty spaces to ABSORB the ECHO. Modern Theatre's have ABSORBENT materials sticked to the walls of the theatre.
(5+6=miles per hour)
i hope this helps
so look...
m=miles
(5m+6=m)<------ answer
hope this helps
Answer:
k > 100
Step-by-step explanation:
y= x²+20x+k
if the graph doesn't intersect the x-axis it means it has no real roots so the discriminat has to be negative so will have imaginary roots
discriminant is
b²-4ac = 20²-4*1*k = 400-4k for this to be negative k has to be more then 100 so will have 400 - a number bigger then 400
k > 100 is the solution
Second pictures it is better
