how long do you have to search for a storm shelter before the tornado wipes everything away?

Question

A tornado is following you at 30 per hour. You're going as fast as you can to a storm shelter. You hear the sound of thunder and lightning that reminds you of the approaching storm. You start counting. It takes 50 seconds for the sound of thunder to reach you. Sound travels at 0.2 miles per second at your altitude. How long do you have before the storm reaches you? Please Help!! Only math problem I can't solve and due tomorrow!! 

Answer 1

Melissa,

 

First, how far is the storm away from you when you last hear it?

   do = st = (sound travel speed)(time till sound reaches you) = (0.2 mps)(50s) = 10 miles away from you.

 

Now, the tornado is moving toward you at a constant average speed of 30 mph.  How long is it going to take to cover that 10 mile separation?  Apply d=st formula again, but solve for t:

 

t = d/s = 10 miles/30mph = (1/3) hours = 20 minutes (since an hour has 60 min).

 

So you have 20 minutes to get into a shelter.