Blow on the back of your hand with your mouth wide open. Your breath will feel hot. Now
Chapter 18, Problem 10(choose chapter or problem)
Blow on the back of your hand with your mouth wide open. Your breath will feel hot. Now tighten your lips into a small opening and blow again. Now your breath feels cool. Why?
Unfortunately, we don't have that question answered yet. But you can get it answered in just 5 hours by Logging in or Becoming a subscriber.
Becoming a subscriber
Or look for another answer