Question

A waterfall has a height of 1000 feet. A pebble is thrown upward from the top of the falls with an initial velocity of 16 feet per second. The

height, h, of the pebble after t seconds is given by the equation h=-161² +16t+1000. How long after the pebble is thrown will it hit the
ground? Use a graphing calculator to solve the problem.
seconds after it is thrown.
The pebble will hit the ground about
(Round to one decimal place as needed.)

Answer 1

Ok, so, this implies h=0 when the pebble hits the ground.

So, - 16t^2 + 24t + 1300 = 0

If we find t, we obtain two solutions, one negative and one positive, so the positive is correct.

Then, t = 9.7950 s

Therefore, it would take about 9.7950 seconds for the pebble to hit the ground.