Quadratic Function Application Problems

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

• 4 seconds

• -2 seconds

• -2 and 4 seconds

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.

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

The function f(t) = -5t²+20t + 60 models the approximate height of an object t seconds after it is launched. How many seconds does it take the object to hit the ground?

• 4 seconds

• -2 seconds

• 6 seconds

• 9 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

The function
f(t) = -5t²+20t + 60 
models the approximate height of an object t seconds after it is launched. How many seconds does it take the object to hit the ground? 

• 4 seconds

• -2 seconds

• 6 seconds

• 9 seconds

A soccer ball is kicked from the ground with an initial upward velocity of 90 feet per second. The equation h=-16t² + 90t gives the height h of the ball after t seconds.
What is the maximum height of the ball?

• 126.56 ft

• 5.625 sec

• 2.81 sec

• 90 ft

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