Quadratics and Projectile Motion

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

• 10 seconds

• 2 seconds

• 5 seconds

• 7 seconds

Must make Equation =0, then quadratic formula or factor

• -3

• 0.4

• 2.5

• 4

Hint: Make equation =0, then type into Desmos and look for x-intercepts.

• -0.5

• 0.5

• 2

• -2

Hint: make equation =0, then put equation into Demos.

• -4

• 2

• -1

• 3

which of the following show the quadratic formula being used properly?

Solve by taking square roots:
5b² - 4 = 41

• b = 9, b = -9

• b = 3, b = -3

• b = 8, b = -8

• no solution

What is the equation that matches the graph?

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

• 4.5 seconds

• 2.5 seconds

• 3.8 seconds

• 3.5 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.
How many seconds did it take for the ball to reach its maximum height?

• 10 seconds

• 64 seconds

• 960 seconds

• 2 seconds