Question

HELP PLEASE!!!!!!!!!! A model rocket is launched with an initial upward velocity of 204 ft/s. The rocket's height h (in feet) after t seconds is given by the following.REST ATTACHED BELOW!!!!!!! HELP ME!!!!! Quickly!!!!!!!!!!

Answer 1

Answer:

t = .51 sec and t = 12.24 sec

Step-by-step explanation:

This is parabolic.  The nature of the parabola is symmetrical about a vertical line, so when an object going up passes a certain height, it will reach its max height and begin to fall, once again passing that certain height, just at a later time.  Besides that, this is a second degree polynomial so we are expecting to have 2 solutions.

If we are looking for the times that the height, h, of the rocket is 100 feet, then we sub in 100 for h and factor to solve for t:

$100=-16t^2+204t$

To factor this, we will move everything over to one side and set the quadratic equal to 0:

$-16t^2+204t-100=0$

Factor this using the quadratic formula to find

t = .51 and t = 12.24 seconds