Question

which of the following statements is the reason why its possible to focus sound?
sound has subjective and objective qualities.
sound travels extremely fast.
the doppler effect is used in radar systems.
sound reflects from the same angle from which it strikes a surface.

Explanation:

Sound can be focused because it reflects from the same angle from which it strikes a surface. This property (similar to light reflection in optics) allows for the design of structures (like parabolic reflectors for sound) that can direct and focus sound waves. The other options: having subjective and objective qualities is about perception and measurement, not focusing; traveling fast is about speed, not focusing; Doppler effect in radar is about frequency change with motion, not focusing.

Answer:

Sound reflects from the same angle from which it strikes a surface.