Thank you for the opportunity to help you with your question!
A) There are 5 numbers next to our first number, so our power of 10 is 5. Now we just need to find out what number times 10^5 equals 360,000. It's 3.6, so our number in scientific notation is 3.6*10^5 miles.
B) To find the time we simply divide the distance by the speed of our rocket:
(3.6*10^5 miles) / (4*10^4 miles per hour) = 9 hours
So it will take the rocket 9 hours to reach the moon.
Please let me know if you need any clarification. I'm always happy to answer your questions.