Quadratic Functions Applications

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?

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?

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

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

Elaine shoots an arrow upward at a speed of 32 feet per second from a bridge that is 28 feet high. The height of the arrow is given by the function h(t) = -16t² + 32t + 28, where t is the time in seconds. What is the maximum height that the arrow reaches?

• 24 ft.

• 30 ft.

• 44 ft

• 32 ft.

The height in meters of a projectile after t seconds is given by ℎ(𝑡) = 160𝑡 − 80𝑡 ² . Find the maximum height that can be reached by the projectile.

• A. 40 m

• B. 80 m

• C. 30 m

• D. 90 m

A person standing close to the edge on the top of an 80-foot tower throws a ball with an initial speed of 64 feet per second. After t seconds, the height of the ball above the ground is s(t) = -16t² + 64t + 80 . After how many seconds will the ball reach its maximum height?

• 2 secs

• 3 secs

• 4 secs

• 5 secs