Answer: Weather balloons are :
3. Objects that carry instruments into the stratosphere to measure atmospheric conditions
Step-by-step explanation:
Weather balloon is a balloon that is filled with hydrogen or helium gas. It has a life of approx. 2 hours. It move very slowly by air force up to a distance of 125 miles away from it's starting point and to a height of over 20 miles.
Weather balloons are made up of latex or neoprene, which a synthetic rubber. Once the balloon bursts, it comes down to ground by the help of a parachute attached to it.
Weather balloons are also called sounding balloons.
The instruments that are carried up by weather balloon send back information on atmospheric conditions by aid of radiosonde.
Radiosonde is a small, expendable, measuring device that transmit information through radio. They measure temperature, atmospheric pressure, humidity and wind direction.