A model airplane is shot up from a platform 1 foot above the ground with an initial upward velocity of 56 feet per second. The hight of the airplane above ground after t seconds is given by the equation h=-16t^2+56t+1 where h is the hight of the airplane in feet and t is the time in seconds after it is launched. Approximately how long does it take the airplane to reach its maximum height?
A)0.3 seconds
B)1.8 seconds
C)3.5 seconds
D)6.9 seconds
Please Help

Question

A model airplane is shot up from a platform 1 foot above the ground with an initial upward velocity of 56 feet per second. The hight of the airplane above ground after t seconds is given by the equation h=-16t^2+56t+1 where h is the hight of the airplane in feet and t is the time in seconds after it is launched. Approximately how long does it take the airplane to reach its maximum height? 
A)0.3 seconds 
B)1.8 seconds 
C)3.5 seconds 
D)6.9 seconds
Please Help

anonymous · Answer

what jerk would shoot down a model airplane! :( It's my favorite toy!

anonymous · Answer

lol

anonymous · Answer

haha an idiot who hates aviation @sourwing I'm a pilot in training so I personally dislike it lol

anonymous · Answer

dont you have a graphing calculator?

anonymous · Answer

yeah but I just don't get it period can you give an explanation @sourwing ?

anonymous · Answer

oh wait, it asks for maximum height -.- 

well, the vertex any parabola is at x = -b/(2a)

anonymous · Answer

vertex *of* any parabola

anonymous · Answer

t = -56 / (2 * -16) <-- ans

anonymous · Answer

this is trigonometry, i believe i am learning about this now. that is a triangle are formula. i would draw it and find where x is located. Then you have to round off the answer. it would be 1.8 
(-56 \0/(2*-16) = 1.75 = 1.8

anonymous · Answer

thanks both of you!!