Question 758309: Liza and Joseph are practicing football. Liza heads out for a pass, running at 6 yards per second. Three seconds after Liza heads out, Joseph throws the football straight towards her, and it travels horizontally at an average speed of 8 yards per second until it reaches Liza. How long in seconds after Joseph throws the football does Liza catch it, assuming that she catches it?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Liza and Joseph are practicing football. Liza heads out for a pass, running at 6 yards per second. Three seconds after Liza heads out, Joseph throws the football straight towards her, and it travels horizontally at an average speed of 8 yards per second until it reaches Liza. How long in seconds after Joseph throws the football does Liza catch it, assuming that she catches it?
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Liza DATA: rate = 6 yds/sec ; time = x seconds: distance = r*t = 6x yds
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Football DATA: rate = 8 yds/sec ; time = x-3 sec: distance = 3(x-3) yds
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Equations:
distance = distance
6x = 8x-24
-2x = -24
x = 12 seconds.
x-3 = 9 seconds (catch after Joseph throws)
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Cheers,
Stan H.
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