Quadratics Initial Height

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

Alain throws a stone off a bridge into a river below. The stone's height (in meters above the water), x seconds after Alain threw it, is modeled by:

h(x)= -5x² + 10x + 15

How many seconds after being thrown will the stone hit the water?

• -1 seconds

• 1 second

• 2 seconds

• 3 seconds

When did the ball reach its maximum height? Choose the key feature and the answer.

• y-intercept, 3 secs

• x-value of the vertex, 4 secs

• y-value of the vertex, 5 secs

• y-intercept, 0 secs

What was the maximum height of the ball? Choose the key feature and the answer choice.

• y-intercept, 3 feet

• y-intercept, 0 feet

• x-value of the vertex, 4 feet

• y-value of the vertex, 5 feet

How high was the ball when it was thrown? Choose the key feature and the answer.

• y-intercept, 0 feet

• y-intercept, 3 feet

• x-value of the vertex, 4

• y-value of the vertex 5

What was the height of the ball at 1 second?

• 3 feet

• 4 feet

• 5 feet

What was the maximum height of the water? Choose the key feature and the answer.

• y-intercept, 0 feet

• x-value of the vertex, 2 feet

• y-value of the vertex 10 feet

• x-intercept. 3.85 feet

What was the height of the water at 3 seconds?

• 9 feet

• 10 feet

• 7 feet

• 5 feet

Approximately how long did it take the water from the fountain to hit the pool below?

• about 1.85 second

• about 2.85 seconds

• about 3.85 seconds

• about 4.85 seconds

Approximately when did the ball hit the ground?

• 3.25 seconds

• 4.25 seconds

• 8.25 seconds

• 10.25 seconds