Quadratic Applications Parabola Word Problem

A rock is dropped from a bridge 320 ft. above a river. The pathway that the rock takes can be modeled by the equation h = -16t² + 320. How long will it take for the rock to reach the river (i.e. hit the "ground")?

• 2.5 sec

• 3.5 sec

• 4.5 sec

• 3.8 sec

An object in launched directly upward and the height of the object is represented by the equation s(t) = –16t² + 64t + 80. What is the initial velocity the object is launched at?

• 64 feet

• 80 feet

• 16 feet

• -16 feet

Amelia runs a catering business. Based on her records, her profit is shown by P = 2x² - 44x -150, where x is the number of meals she caters and P is her profit. When P is negative, Amelia loses money. What is the least number of meals Amelia needs to cater in order to begin making profit?

• -1

• 5

• 11

• 25

• 50

When I want to find the maximum or minimum height of an object, I should_____

• Set the equation = 0 and solve.

• Use x = (-b/2a) as my answer.

• Substitute x = 0 into the equation.

• Find the y-coordinate for the vertex.

If I want to find out when an object hits the ground, I should _________.

• Use x = (-b/2a) as my answer.

• Set my equation = 0 and solve.

• Replace x with 0 and evaluate.

• Find the y-coordinate of the vertex.

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

Tags

CCSS.HSF-IF.C.7A

If path of a projectile is modeled by: 
h(t) = -16t² + 20t +6, what is the height after 1 second? 

• 6 feet 

• 20 feet 

• 10 feet 

• 4 feet