11.12.25: Quadratic W.P. Practice

Heather dropped a water balloon over the side of her school building from a height of 80 feet. The approximate height of the balloon at any point during its fall can be represented by the following quadratic equation:

h = -16t² + 80

About how long did it take for the balloon to hit the ground?

• 1.73 seconds

• 2.24 seconds

• 2.45 seconds

• 2.83 seconds

Rafael drops a ball from a third-story window. This equation represents the approximate height, h, in meters, of the ball above the ground after it falls for t seconds.

h = -5t² + 45

When is the ball at ground level?

• only at t = 0 seconds

• only at t = 3 seconds

• only at t = 9 seconds

• at both t = 0 seconds and t = 3 seconds

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

Solve the word problem: How fast would you reach the water if you jump of a cliff using the formula: h(t) = -16t² + 8t + 24?

• 8

• 1

• 1.5

• 1/4

A frog is sitting on the ground when he is scared by a big dog. His movement is modeled by the equation h = -6t² + 6t where h is the frog's height at any given time, t . How many seconds until the frog is back on the ground?

• 0.5 seconds

• 1 second

• 1.5 seconds

• 2 seconds

• 3 seconds

A frog is sitting on the ground when he is scared by a big dog. The movement of the frog is modeled by the equation

h = -6t² + 6t where h is the frog's height at any given time, t. How high does the frog jump?

• 0.5

• 1

• 1.5

• 2

• 5

How high would you jump if the equation for jumping from a cliff is:    
h(t) = -16t² + 8t + 24?

• 25
• 24
• 8
• 26

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

In order to find the vertex of an in standard form, the first two steps are to use the equation _____ to find the x value, and then you can plug that value back into the equation to find the _____.

• -b/2a, y-value
• (x-h)^2, y-intercept
  
• (x-r1), solution
• ax^2, vertex

The area of a playground is 336 yd2 . The width of the playground is 5 yd longer than its length. Find the length and width of the playground

•  length = 26 yd, width = 21 yd
• length = 21 yd, width = 26 yd 
• length = 21 yd, width = 16 yd 
• length = 16 yd, width = 21 yd