SOLUTION: I just don't know how to set this problem up. I need help!
Ely stands next to his cousin Teri. He shoots his bb-gun at a straight horizontal angle. Teri records the time it tak
Question 149101: I just don't know how to set this problem up. I need help!
Ely stands next to his cousin Teri. He shoots his bb-gun at a straight horizontal angle. Teri records the time it takes from the moment Ely fires the bb-gun until the sounds of the ping(the bb hitting the can) to return, .25 seconds. The distance is 20 yards. The speed of sound is 1140 ft per sec. How fast does the bb travel? Hos far did the bb fall? The equation he gave us h=-16t^2+vt+h Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Ely stands next to his cousin Teri. He shoots his bb-gun at a straight horizontal angle. Teri records the time it takes from the moment Ely fires the bb-gun until the sounds of the ping(the bb hitting the can) to return, .25 seconds. The distance is 20 yards. The speed of sound is 1140 ft per sec. How fast does the bb travel? How far did the bb fall? The equation he gave us h=-16t^2+vt+h
:
Let x = velocity of the bb
:
Write a time equation: Time = dist/speed
:
Distance for the sound and the bb = 20 yds which = 60 ft (since we're dealing in ft/sec}
:
Return sound time + bb transit time = .25 sec + = .25
:
Multiply equation 1140x and you have:
60x + 1140(60) = 1140x * .25
:
60x + 68400 = 285x
:
68400 = 285x - 60x
:
68400 = 225x
x =
x = 304 ft/sec, velocity of the bb gun
:
:
How far did the bb fall:
Find the transit time of the bb = .197368 sec to travel 60 ft
The horizontal velocity does not affect the fall distance, only the transit time and gravity (-16t^2)
-16*.197368^2 = -.03895 ft or about .467 inches
