Here are the answers to your questions based on the principles of sound:
Question 1:
What medium does sound travel through slowest?
Answer: gas
Question 2:
Which item will sound travel faster through if each medium is at 20 degrees Celsius?
Answer: aluminum
Question 3:
A plane is flying overhead. Will a person on the ground hear the airplane sooner on a cold day or a warm day and why?
Answer: The sound will travel faster on a warm day because the air particles have more kinetic energy and are moving faster.
(Option 2)
Question 4:
Why is sound able to travel faster through a solid than a gas?
Answer: Solid molecules are packed tightly.
Question 5:
Sound is caused by....
Answer: vibrations
Let me know if you need any additional information!