Question

PLEASE GIVE STEP BY STEP EXPLANATION .
A man stands between two parallel cliffs (not in middle). When he claps his hands, he hears two
echoes one after 1 second and other after 2 seconds. If the velocity of sound in air is
330 ms-1, the width of the valley is
(1) 330 m
(2) 495 m
(3) 660 m
(4) 990 m​

Answer 1

Answer:

The plasma membrane, also called the cell membrane, is the membrane found in all cells that separates the interior of the cell from the outside environment. In bacterial and plant cells, a cell wall is attached to the plasma membrane on its outside surface.

Step-by-step explanation:

I hope it is helpful for