An instrument used to measure wind speed is a(n)
a. weather vane
c. anemometer
b. wind sock
d. barometer

The correct answer is C. An anemometer

Explanation

An anemometer is a device that determines the speed of the wind, anemometers are usually composed by a set of revolving cups or vanes that twirl according to the wind and that activate an electric generator or a counter that determines the speed of the wind. On the other hand, weather vanes and windsocks are instruments use to know the direction of the wind, but no its speed and barometers are used to determine the atmospheric pressure, which is not related to wind.

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.

no the answer is c only objects touching the earth's surface can be acted upon by an outside force