Quiz on Quadratics 2

Suppose the equation h(t) = –t² + 5t + 14 models the height of a ball thrown into the air off the bleachers. Which statement about the flight of the ball is true?

• The ball starts from a height of 19 feet.

• The ball takes 5 seconds before it hits the ground.

• The ball takes 14 seconds before it hits the ground.

• The ball reaches a maximum height of 20.25 feet.

Hampton Furniture produces couches in its factory. The quadratic function, p(n) = –15n² + 615n – 600, can be used to determine the company’s weekly profit where n is the number of couches made. What is the largest number of couches the factory can produce in 1 week and still make a profit?

• 20

• 21

• 39

• 40

James kicked a ball off the ground into the air. The function h(t) = –16t² + 40t models the height (in feet) of the ball tseconds after it was kicked. How long did it take the ball to hit the ground after being kicked?

• 1.25 seconds

• 2.5 seconds

• 4 seconds

• 10 seconds

Two rockets were launched from a rooftop. The heights of the rockets x seconds after being launched are modeled by the functions shown below.

Rocket F: f(x) = –4x² + 29x + 24

Rocket G: g(x) = –5x² + 26x + 24

Which statement is true?

• Rocket F hit the ground 2 seconds before Rocket G.

• Rocket F hit the ground 3 seconds after Rocket G.

• Rocket F hit the ground 3 seconds before Rocket G.

• Rocket F hit the ground 2 seconds after Rocket G.

A ball was kicked straight up into the air from at a velocity of 80 feet per second. The function h(t) = –16t² + 80t models the height of the ball t seconds after it was kicked. For how many seconds is the ball descending?

• 2.0 seconds

• 2.5 seconds

• 3.5 seconds

• 5.0 seconds

A company produces swimming pools. Its daily cost can be modeled with the function P(x)=20x² – 240x, where x is the number of swimming pools produced. If the company makes at least 1 pool a day, how many pools need to be produced for the company to break even?

• 3

• 6

• 12

• 15

Steve threw a ball into the air. The height of the ball t seconds after it was thrown into the air is modeled by the function h(t) = –16t² + 40t + 144. How long does it take the ball to hit the ground?

• 1.25 seconds

• 2.0 seconds

• 2.5 seconds

• 4.5 seconds