Question

A bird drops a stick to the ground from a height of 68 ft. The function h= -16r² +68 gives the stick's approximate height h above the ground, in feet, after t seconds. At about what

time does the stick hit the ground?

Answer 1

Answer: 2.05 seconds.

Explanation:

The function h = -16r² + 68 gives the height of the stick above the ground in terms of time r. When the stick hits the ground, its height is 0 feet. We can set h = 0 and solve for r to find the time at which the stick hits the ground:

0 = -16r² + 68

Adding 16r² to both sides, we get:

16r² = 68

Dividing both sides by 16, we get:

r² = 4.25

Taking the square root of both sides, we get:

r = 2.05

Since r is in seconds, the stick hits the ground at approximately 2.05 seconds.