Quadratic Applications

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 

An object in launched directly upward at 64 feet per second (ft/s) from a platform 80 feet high. Its height is represented by the equation 
s(t) = –16t² + 64t + 80.
What will be the object's maximum height? 

• 2 ft

• 80 ft

• 144 ft

• 64 ft

What is the initial (starting) height of an object following this path?  h(t) = -16t² +20t + 6

• -16 feet 

• 0 feet

• 20 feet 

• 6 feet 

To calculate the TIME that a maximum height occurs, you should use: 

• -b/(2a) 

• Quadratic formula 

• the c value 

• 0

For that same projectile, at what TIME does the maximum height occur? 
h(t) = -16t² + 20t + 6 

• 0 seconds 

• 625 seconds 

• 160 seconds 

• 2 seconds 

To calculate the maximum height, you should: 

• Use the time you got from -b/(2a) and plug it in for each "t" 

• -b/(2a) 

• use the c value 

• use the b value 

What is the maximum height for that same projectile? (time of maximum height was .625) 
h(t) = -16t² + 20t + 6 

• 8.5 feet 

• 12.25 feet 

• 24.75 feet 

• 6 feet 

If we are trying to find out when an object hits the GROUND, what should we put in for "h"?

• 0

• 1

• 2

• 3

A lizard is jumping across the water in search of food. The equation h = -12t² + 6t models the lizard's height in feet above the water t seconds after he jumps. How long after jumping is he back on the water?

• 0.1 seconds

• 0.25 seconds

• 0.50 seconds

• 0.75 seconds

• 1 second

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.