Quadratic Functions Real World Problems

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 ball is thrown into the air with an upward velocity of 100 ft/s. Its height, h, after t seconds is given by the function
 h = -16t² + 64t + 960.
When did the ball hit the ground?

• 10 seconds

• 2 seconds

• 5 seconds

• 7 seconds

A diver is standing on a platform above the pool. He jumps form the platform with an initial upward velocity of 8 ft/s. The following functions reprsents the divers height (in feet) where t is time in seconds: h(t) = −16 t² + 8t + 24How high is the platform?

• .25 ft

• 24 ft

• 25 ft

• 8 ft

A ball is thrown into the air with an upward velocity of 40ft/s. Its height h in feet after t seconds is given by the function : h(t) = -16t^2 + 40t + 10 How many seconds does it take the ball to reach its maximum height?

• 1.25 seconds

• 1.4 seconds

• 2.5 seconds

• 2 seconds

You jump off a 24 foot high cliff and your fall is modeled by the function:

h(t) = -16t² + 8t + 24

How long would it take you to hit the water?

• 8 seconds

• 1 second

• 1.5 seconds

• 1/4 second

Jason jumped off of a cliff into the ocean in Acapulco while vacationing with some friends. His height as a function of time could be modeled by the function h(t) = –16t² + 16t + 480, where t is the time in seconds and h is the height in feet. How long does it take Jason to hit the water?

• -16 seconds

• -6 seconds

• 0 seconds

• 6 seconds

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

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

A ball is thrown vertically into the air. Its height in feet after t seconds is given by the equation h(t) = –5t² + 20t. How many feet into the air will the ball be at 3 seconds?

Mathematical Equivalence

OFF

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. 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