Question

For reflection of sound wave we need ____________
a) a highly polished mirror
b)A concave mirror painted blue
c)A large opaque reflecting surface
d)A glass plate.
Which is the most appropriate answer?Give reasons.

Answer 1

a highly polished mirror

Answer 2

We need a flat,smooth , hard and stiff surface.

Opaque reflecting surface would be good only if it is smooth and flat.
Concave doesn't reflect well as the convex does.
Glass plate is not a good option as it may not be smooth and stiff..

So our best option is A) Highly polished mirror.
It is flat, smooth ,hard and also stiff.
It may not be very hard but it is still harder than glass.

Hope This Helps!