The scientists tested a hypothesis on running in the rain performed only one controlled experiment that supported their hypothesis. can their supported hypothesis be called a theory?

No it cannot because you would have to test it over and over again to make sure it was correct the first time.

The objects do not reach terminal velocity         there is not enough time from the time the object falls from when it hits the ground to achieve terminal velocity. an object must be placed higher to achieve terminal velocity in order to be in free fall.