Physics help needed!

• Darkness_hacker99

  23 Sep 07, 11:18

  Lets say I am standing at a point, from a cliff, 1 side 330m 1 side 660m, and assume the sound is traveling at the speed of 330m per Sec, how long is the time difference between 1st and 2nd echo?
  
  edit:typo
• AndrewPKYap

  23 Sep 07, 11:29

  Originally posted by Darkness_hacker99:

  Lets say I am standing at a point, from a cliff, 1 side 330m 1 side 660m, and assume speed travel 330m per Sec, how long is the time difference between 1st and 2nd echo?
  

  What is the meaning of "assume speed travel 330m per Sec"?
• Agenda

  23 Sep 07, 11:33

  Originally posted by Darkness_hacker99:

  Lets say I am standing at a point, from a cliff, 1 side 330m 1 side 660m, and assume speed travel 330m per Sec, how long is the time difference between 1st and 2nd echo?
  

  taking this diagram
  
  <-------660m------- YOU ---330m-->
  
  if there is no direction specified..
  
  i would assume that the echo travels both sides, then the time you will hear echo is
  
  660m = 4 sec
  330m = 2 sec
• Darkness_hacker99

  23 Sep 07, 11:43

  Originally posted by Agenda:

  taking this diagram
  
  <-------660m------- YOU ---330m-->
  
  if there is no direction specified..
  
  i would assume that the echo travels both sides, then the time you will hear echo is
  
  660m = 4 sec
  330m = 2 sec

  Thanks! This is what I thought too!
  
  So the difference will be 4 sec minus 2 sec = 2 sec.
• AndrewPKYap

  23 Sep 07, 11:44

  Originally posted by Darkness_hacker99:

  Lets say I am standing at a point, from a cliff, 1 side 330m 1 side 660m, and assume speed of sound travel 330m per Sec, how long is the time difference between 1st and 2nd echo?
  
  edit:typo

  What is the meaning of the "speed of sound travel at"?
• Darkness_hacker99

  23 Sep 07, 11:48

  Originally posted by AndrewPKYap:

  What is the meaning of the "speed of sound travel at"?

  Because we need to know the speed of sound and distance to find out the time(in seconds) echo is heard.
• AndrewPKYap

  23 Sep 07, 11:51

  Originally posted by Darkness_hacker99:

  Because we need to know the speed of sound and distance to find out the time(in seconds) echo is heard.

  are you sure the phrase " the "speed of sound travel at"?" is meaningful? How does "speed of ANYTHING TRAVELS"?
  
  Things move (travel) but how does the speed of SOMETHING travels?
• Darkness_hacker99

  23 Sep 07, 11:53

  Originally posted by AndrewPKYap:

  are you sure the phrase " the "speed of sound travel at"?" is meaningful? How does "speed of ANYTHING TRAVELS"?
  
  Things move (travel) but how does the speed of SOMETHING travels?

  Ok. I go edit it. Guess it's just my mistake.
• HyuugaNeji

  23 Sep 07, 11:55

  the speed of lorry is 50km/h
  the speed of lorry travels at 50km/h (this part is wrong)
  
  ya 4-2=2
• AndrewPKYap

  23 Sep 07, 11:56

  Originally posted by HyuugaNeji:

  the speed of lorry is 50km/h
  the speed of lorry travels at 50km/h

  the lorry is traveling at a speed of 50km/h
• AndrewPKYap

  23 Sep 07, 11:57

  Originally posted by HyuugaNeji:

  ya 4-2=2

  eh?
• Darkness_hacker99

  23 Sep 07, 11:59

  Originally posted by HyuugaNeji:

  ya 4-2=2

  Thanks!
• eagle

  23 Sep 07, 14:07

  Originally posted by Darkness_hacker99:

  Thanks!