Question

The obstacle should be rigid such as building or hill
The obstacle should be a very large sheet cloth
12
Ir the air in the room warms up the speed of sound
Increases
Remains same
Decreases d
luctus
IN
For reflection of sound wave we need
A polished mimo
A Concave surface
A large opaque reflecting surfaced
A glass plate
19
Distance of crest from mean position is called
Amplitude
frequency
displacement
d
Wavelength
A pulse is a disturbance
of short duration
of long duration
Wie vacum d
Which travels in only​

Answer 1

so dear fool study harder ok sorry for that noob hahahahaha

Explanation:

it's a dare for to do sorry sorry sorry