A pebble is tossed from the top of a cliff. The pebble's height in feet is given by y(t) = -16t2 + 6t + 200, where t is the time in seconds. Its horizontal distance in feet from the base of the cliff is given by d(t) = 5t. How far will the pebble be from the base of the cliff when it hits the ground? Round to the nearest foot. _______ ft Use a number only.

Question

A pebble is tossed from the top of a cliff. The pebble's height in feet is given by y(t) = -16t2 + 6t + 200, where t is the time in seconds. Its horizontal distance in feet from the base of the cliff is given by d(t) = 5t. How far will the pebble be from the base of the cliff when it hits the ground? Round to the nearest foot.  _______ ft   Use a number only.

anonymous · Answer

When the pebble is on the ground the height y(t)=0. So set -16t^2 + 6t + 200=0 and solve for t. Then to find the horizontal distance, use this value of t in the d(t) equation for distance

anonymous · Answer

@AudrianaS did you get it?

anonymous · Answer

well, what do i use to solve for t?

anonymous · Answer

use Quadratic formula .
are you familiar with it?

anonymous · Answer

yes

anonymous · Answer

so what did you get after solving
$$\Large -16t^2 + 6t + 200=0$$

??

anonymous · Answer

well right now im kinda stuck on
 |dw:1343674807069:dw|