A firecracker shoots up from a hill 150 feet high, with an initial speed of 110 feet per second. Using the formula H(t) = -16t2 + vt + s, approximately how long will it take the firecracker to hit the ground?

Question

anonymous · Answer

Eight seconds 

 Nine seconds 

 10 seconds 

 11 seconds

anonymous · Answer

@ganeshie8 @jigglypuff314

anonymous · Answer

@iambatman @wio @kelliegirl33

anonymous · Answer

@Destinymasha @blues @SithsAndGiggles

campbell_st · Answer

well substituting the initial height and velocity you get 

H(t) = $$H(t)=-16t^2 +110t + 150$$

to find when it hits the ground, let H(t) = 0... so height = 0

and then solve for t. 

perhaps general quadratic formula is easiest

campbell_st · Answer

only use the positive answer as time can't be negative