A Thermometer: measures the air temperature.
A wind vane: determines the direction from which the wind is blowing from.
An Anemometer: measures wind speed.
A Hygrometer: measures the water vapor content of air or the humidity.
A Barometer: measures air pressure
Answer:
the balloon and soda can will do nothing, while the two balloons will repel each other
Explanation:
opposites attract and the soda can is too heavy to be attracted to the balloon
