Quadratic Applications Warmup

Alain throws a stone off a bridge into a river below. The stone's height (in meters above the water), x seconds after Alain threw it, is modeled by:

h(x)= -5x² + 10x + 15

How many seconds after being thrown will the stone hit the water?

• -1 seconds
• 1 second
• 2 seconds
• 3 seconds

Alain throws a stone off a bridge into a river below. The stone's height (in meters above the water), x seconds after Alain threw it, is modeled by:
h(x)= -5x² + 10x + 15
How high above the water is the stone when Alain throws it?

• -5 meters
• 0 meters
• 10 meters
• 15 meters

Alain throws a stone off a bridge into a river below. The stone's height (in meters above the water), x seconds after Alain threw it, is modeled by:
h(x)= -5x² + 10x + 15
How long does it take the stone to reach its highest point?

• 1 seconds
• 1.5 seconds
• 2 seconds
• 3 seconds

Alain throws a stone off a bridge into a river below. The stone's height (in meters above the water), x seconds after Alain threw it, is modeled by:
h(x)= -5x² + 10x + 15
What is the maximum height of the stone?

• 15 meters
• 16.5 meters
• 20 meters
• 22.2 meters

Alain throws a stone off a bridge into a river below. The stone's height (in meters above the water), x seconds after Alain threw it, is modeled by:
h(x)= -5x² + 10x + 15
How high will the stone be above the water after 1.2 seconds?

• 0 meters
• 15 meters
• 19.8 meters
• 22.2 meters

Alain throws a stone off a bridge into a river below. The stone's height (in meters above the water), x seconds after Alain threw it, is modeled by:
h(x)= -5x² + 10x + 15
After how many seconds will the rock be 17 meters above the water?

• 0.23 seconds and 1.78 seconds
• 0.18 seconds and 2.12 seconds
• 1.56 seconds
• 0.57 seconds and 2.69 seconds

The length of a rectangle is 3 inches more than its width. The area of the rectangle is 70 square inches. Find the length of the rectangle.

• 5 inches
• 7 inches
• 10 inches
• 14 inches

You are trying to dunk a basketball. You need to jump 2.5 feet in the air to dunk the ball. The height that your feet are above the ground is given by the function:
h(t) = -16t² + 12t
Will you be able to dunk the basketball?

• Yes
• No
• As long as I'm wearing Air Jordans

The length of a rectangular flower garden is 2 less than 3 times the width. Find the dimensions of the garden if the area is 65 square feet.

• W = 5 meters, L = 13 meters
• W = 4 meters, L = 16.25 meters
• W = 6.5 meters, L = 10 meters
• W = 8 meters, L = 8.13 meters