Question

9.3. Answer the following. (any 3)
1)An object is placed at distance of so em from concave mirror of focal lenge 16 cm finde
2. Complete the table
Type of sound. Frequency
1. Audible sound. a) b) Less than 20HZ 2.___________. b) Less than 20Hz
3.Ultra sound. c)____________​

Answer 1

Answer:

2. ifrasonic sound

c more than 20 Hz