Quadratic Functions Solutions and Word Problems

If a toy rocket is launched vertically upward from ground level with an initial velocity of 128 feet per second, then its height h after t seconds is given by the equation
h(t) = -16t² +128t  
When will the object reach its maximum height?

• 4 ft
• 0 seconds
• 0 ft
• 4 seconds

The profit from selling local ballet tickets depends on the ticket price.  Using past receipts, we find that the profit can be modeled by the function
p= -15x² +600x +60 , where x is the price of each ticket.  What is the maximum profit you can make from selling tickets?

• $6060
• $20
• $600
• $10,250

If each mark on the x-axis represents one second, when did the object reach the ground?

• 2.5 seconds
• 6 seconds
• 5.5 seconds
• 5 seconds

An object in launched directly upward at 64 feet per second (ft/s) from a platform 80 feet high. Its height is represented by the equation s(t) = –16t² + 64t + 80. What will be the object's maximum height? 

• 2 ft
• 80 ft
• 144 ft
• 64 ft

Rafael drops a ball from a third-story window. This equation represents the approximate height, h, in meters, of the ball above the ground after it falls for t seconds.
h = -5t² + 45 
When is the ball at ground level?

• only at t = 0 seconds 
• only at t = 3 seconds
• only at t = 9 seconds
• at both t = 0 seconds and t = 3 seconds

Jason launched a rocket for a physics experiment. This equation can be used to find the height (h), in feet, of the rocket after t seconds. 
h = -16t2 + 288t + 8
How many seconds will it take for the rocket to reach a height of 1,304 feet? 

• 9.0 seconds 
• 9.6 seconds
• 81.0 seconds
• 82.0 seconds

Solve for h:
0 = (h – 7)(2h + 3)

• h = –14 or h = 12
• h = –7 or h = 3
• h = 7 or h = -3/2
• h = –14 or h = -3/2

If f(x) = -3x² + 5x, what is the value of f(-1)?

• 2
• -2
• -8
• 8

What are the roots of the function
f(x)= (x - 2)(x + 3)?

• x = - 2 or x = 3
• x = 2 or x = -3
• The are no real roots
• x = 2 or x = 3

A ball is thrown into the air with an upward velocity of 100 ft/s. Its height, h, after t seconds is given by the function
 h = -16t² + 64t + 960.
How many seconds did it take for the ball to reach its maximum height?

• 10 seconds
• 64 seconds
• 960 seconds
• 2 seconds