SOLUTION: The formula s=-16t^2 + vt + s gives you the height in feet above the earth at time t seconds for an object projected into the air with an initial velocity of v feet per second (ft/

Algebra ->  Inequalities -> SOLUTION: The formula s=-16t^2 + vt + s gives you the height in feet above the earth at time t seconds for an object projected into the air with an initial velocity of v feet per second (ft/      Log On


   

Question 222775: The formula s=-16t^2 + vt + s gives you the height in feet above the earth at time t seconds for an object projected into the air with an initial velocity of v feet per second (ft/sec) from an initial height of s feet. Two balls are thrown into the sir simultaneously, one from the ground at 40 ft/sec and one from a height of 20 feet at 30 ft/sec. For what values of t will their heights above the ground differ by 10 feet or less?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The formula s=-16t^2 + vt + s gives you the height in feet above the earth at time t seconds for an object projected into the air with an initial velocity of v feet per second (ft/sec) from an initial height of s feet.
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Two balls are thrown into the sir simultaneously, one from the ground at 40 ft/sec and one from a height of 20 feet at 30 ft/sec.
1st ball: s(t) = -16t^2+40t+0
2nd ball: s(t) = -16t^2+30t+20
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For what values of t will their heights above the ground differ by 10 feet or less?
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Equation:
height - height <= 10 feet
(-16t^2+30t+20) - (-16t^2+40t) <= 10
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-10t+20 <= 10
-10t <= -10
t >= 1 second (the heights will differ by at least 10 ft after the 1st second
and until one of the balls reaches the ground.
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Cheers,
Stan H.