Can You Calculate the Rock's Speed Without Considering Sound Delay?

AI Thread Summary
To calculate the speed of the rock, the time it takes for sound to travel back must be considered. Given that the speed of sound is 330 m/s, the time for sound to travel 50 m is approximately 0.15 seconds. Therefore, the time for the rock to reach the bell is 4.5 seconds minus this sound travel time, resulting in about 4.35 seconds. Using the formula v = d/t, the speed of the rock can be calculated as 50 m divided by 4.35 seconds, yielding a speed of approximately 11.49 m/s. This approach effectively incorporates the delay caused by sound travel in determining the rock's speed.
katyross
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Homework Statement


"A rock thrown horizontally at a large bell 50m away is heard to hit the bell 4.5 seconds later. If the speed of sound is 330m/s, what was the speed of the rock? (Disregard the effect of gravity.) [Hint: If it requires a time of t for the sound to return, then it requires (4.5 s-t) for the stone to reach the bell]


Homework Equations



v = d/t

The Attempt at a Solution



Would you completely disregard the speed of sound, and continue using the v= d/t?

v = 50 / 4.5
v = 11.1 m/s
 
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No, I would use the speed of sound, and the hint.
 
how would you fit that into the forumla to find the speed of the rock?
 
katyross said:
how would you fit that into the forumla to find the speed of the rock?

It tells you that if t is the time the sound takes to travel from the bell to your ear, then (4.5-t) is the amount of time the stone takes to travel to the bell.

How can you calculate t, given the speed of sound and the distance travelled?
 
v = d/t

t= d/v
(4.5-t) = 50/330

?
 

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