Elias hits a ball into the air. The equation h=-16t^2+60t+3 models the hight (h) in feet of the ball after t seconds.

I don't really understand how long the ball is in the air.

Question

Elias hits a ball into the air. The equation h=-16t^2+60t+3 models the hight (h) in feet of the ball after t seconds.

I don't really understand how long the ball is in the air.

anonymous · Answer

wat we have to find out...

anonymous · Answer

how long the ball is in the air

anonymous · Answer

Can u recheck ur question...i feel something is missing...

anonymous · Answer

ok, so a girl his a ball into the air... the equation h=-16t^2+60t+3 models the height (h) in feet of the ball after t seconds. How long is the ball in the air?

anonymous · Answer

i meant to say "hits" a ball.

anonymous · Answer

srry. i have to go.

hartnn · Answer

the ball will remain in the air till the height becomes zero,that is when it hits the ground.....so put h=0 .......then u will get a quadratic equation in t which solved gives u time t....can u solve that quadratic equation?

anonymous · Answer

yeah, one sec...

anonymous · Answer

hmm. i think i did something wrong. i know the quadratic equation, but i ended up so far with: -60 plus or minus the square root of 3792 divided by -32.

hartnn · Answer

do u know any other method of solving quadratic equation??
because factorising is much simpler here.....

anonymous · Answer

ok

anonymous · Answer

so, i have to find what minus 60 will give me -48 now, right?

anonymous · Answer

60-12=48. but 12 - 60= -48!

hartnn · Answer

can u use calculator? then u can find root of 3792 easily and what u had done becomes more simpler because of calculator.....

anonymous · Answer

-16t^2+12t+48t+3, right?

hartnn · Answer

nopes....12+48=60 but 12*48 does not equal 3*16....
but can u use calculator?

anonymous · Answer

ok

anonymous · Answer

the square of 3792 is 61.6, rounded

hartnn · Answer

ok so in -60 plus or minus the square root of 3792 divided by -32.
now u have (-60-61.6)/(-32) ......solve this using calcy...

anonymous · Answer

ok

anonymous · Answer

-.05,3.8!

hartnn · Answer

since time cannot be negative u have t=3.8
so the ball will be in the air for 3.8 seconds :)

anonymous · Answer

right, because 3.8 is the only sensible answer to the problem! that was my last problem! thanks so much, and have a great school year!!

hartnn · Answer

:D i completed my school years ago......

anonymous · Answer

oh :)

anonymous · Answer

bye

hartnn · Answer

bye :)