Question

1)State two conditions necessary for hearing an echo.
2)What is the radius of curvature of a spherical mirror whose focal length is -0.5 cm? Also name the type of mirror?​

Answer 1

you must be in a silent place and human ears can't hear echo animals can hear

Explanation:

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Answer 2

Answer:

HERE IS YOUR ANSWER

Explanation:

1). The conditions necessary for hearing the echo:

1). The conditions necessary for hearing the echo: *The human ear can not distinguish between two successive sounds if the period between them is less than 0.1 second , Wide and big reflecting surface must be presented to hear the echo such as the walls , the mountains or the water bodies .