Week 24 CMT Style Problem - 7th Grade

Lightning Strikes

One way to estimate the distance from you to where lightning strikes is to count the number of seconds until you hear the thunder, and then divide by five. The number you get is the approximate distance in miles. People are standing at the four points A, B, C and D. They saw lightning strike at point E. Because sound travels more slowly than light, they did not hear the thunder right away.

1. Who heard the thunder first? Why?
   
   
2. Who heard it last? Why?
   
   
3. One of the people heard it after 12 seconds. Who was it? Explain your answer.
   
   
4. After how many seconds did the person at B hear the thunder? Show how you know.
   
   
5. Now suppose lightning strikes again at a different place. The person at A and the person at C both hear the thunder after the same amount of time. Show on the map below where the lightning might have struck.
   
   
6. In question 5, are there other places where the lightning could have struck? If so, show as many of those places as you can.
7. Lightning struck again! The person at point A heard the thunder 5 seconds after she saw the lightning. Show 3 other spots where the lightning could have struck.
8. The person at point C heard the thunder from that same lightning bolt 15 seconds after the lightning struck. Show where the lightning could have struck.