ALG Quadratic Applications

If I want to see the initial height of an object, I should _____________.

• Substitute x = 0 into the equation and evaluate.

• Use x = (-b /2a) as my answer.

• Find the y-coordinate of the vertex. 

• Set my equation = 0 and solve.

A fountain shoots water in an arc over a lake that can be modeled by the graph of the equation y= -0.4x² + 8x where x is the horizontal distance (in feet) from the fountain base and y is the height (in feet) above the river.  How high does the water go?

• It goes 11.78 feet high

• It goes 20 feet high

• It goes 40 feet high

• It goes 10 feet high

If the graph shows price vs profit, what is the maximum profit? 

• 35

• 12,000

• 12,500

• 60

If path of a projectile is modeled by: 
h(t) = -16t² + 20t +6, what is the height after 1 second? 

• 6 feet 

• 20 feet 

• 10 feet 

• 4 feet 

A raft is dropped from a helicopter 256 feet in the air above the ocean.  Its approximate height, h, after t seconds is given by the function h(t) = -16t² + 256.  How many seconds did it take the raft to hit the water? 

• -4

• 2

• 4

• 8

What is the initial (starting) height of an object following this path?  h(t) = -16t² +20t + 6

• -16 feet 

• 0 feet

• 20 feet 

• 6 feet 

An object in launched directly upward and the height of the object is represented by the equation s(t) = –16t² + 64t + 80. What is the initial velocity the object is launched at?

• 64 feet

• 80 feet

• 16 feet

• -16 feet

Which one are we looking for?

Elliot wants to know how high the soccer ball will get if he kicks it straight up in the air.

• x at vertex

• y at vertex

• positive zero

• y-intercept

Which one are we looking for? Jaiden wanted to know the initial height of a baseball when it was hit at home plate.

• x at vertex

• y at vertex

• positive zero

• y-intercept

Which one are we looking for?

Darrell is trying to find out how many seconds it will take a golf ball to get to its highest point after being hit on the golf course.

• x at vertex

• y at vertex

• positive zero

• y-intercept