Linear and Quadratic Application

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

If I want to find out when an object hits the ground, I should _________.

• Use x = (-b/2a) as my answer.

• Set my equation = 0 and solve.

• Replace x with 0 and evaluate.

• Find the y-coordinate of the vertex.

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

h(t) = -16t² + 20t +6, what is the height after 1 second?

• 6 feet 

• 20 feet 

• 10 feet 

• 4 feet 

• 4 seconds

• -2 seconds

• -2 and 4 seconds

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

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 

Amelia runs a catering business. Based on her records, her profit is shown by P = 2x² - 44x -150, where x is the number of meals she caters and P is her profit. When P is negative, Amelia loses money. What is the least number of meals Amelia needs to cater in order to begin making profit?

• -1

• 5

• 11

• 25

• 50

• Linear

• Exponential

• Quadratic

• None of these