An object is launched from a platform. Its height (in meters), x seconds after the launch, is modeled by:h(x)=−5x2+20x+60How many seconds after launch will the object land on the ground?seconds
Q. An object is launched from a platform. Its height (in meters), x seconds after the launch, is modeled by:h(x)=−5x2+20x+60How many seconds after launch will the object land on the ground?seconds
Equation setup: We have the equation: h(x)=−5x2+20x+60To find when the object will land on the ground, we need to find the value of x when h(x)=0.Set the equation equal to zero: −5x2+20x+60=0
Quadratic formula: To solve the quadratic equation−5x2+20x+60=0, we can use the quadratic formulax=2a−b±b2−4ac, where a=−5, b=20, and c=60.
Calculate solutions: Since the discriminant is positive, we have two real solutions. Now, calculate the two possible values for x using the quadratic formula:x=2⋅−5−20±1600x=−10−20±40
Simplify solutions: Calculate the two solutions:First solution: x=−10−20+40Second solution: x=−10−20−40
Choose physically meaningful solution: Simplify both solutions:First solution: x=−1020First solution: x=−2 (This solution is not physically meaningful, as time cannot be negative.)Second solution: x=−10−60Second solution: x=6
Choose physically meaningful solution: Simplify both solutions:First solution: x=−1020First solution: x=−2 (This solution is not physically meaningful, as time cannot be negative.)Second solution: x=−10−60Second solution: x=6Choose the physically meaningful solution, which is x=6 seconds. This is the time after launch when the object will land on the ground.
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