An object is thrown upward off the top of a 64-foot building, with an initial velocity of 48 feet per second. The height (h) of the object after t seconds is given by the quadratic equation h=-16t^2 +48t +64 When will the object hit the ground?

Question

An object is thrown upward off the top of a 64-foot building, with an initial velocity of 48 feet per second.  The height (h) of the object after t seconds is given by the quadratic equation h=-16t^2 +48t +64 When will the object hit the ground?

anonymous · Answer

@Ellie202000 @confluxepic @SolomonZelman @trinajoy @mathstudent55

anonymous · Answer

Yes my friend

anonymous · Answer

hi

anonymous · Answer

If a ball is thrown vertically upward from the roof of 64 foot building with a velocity of 64 ft/sec, its height after t seconds is s(t)=64+64t–16t2 . What is the maximum height the ball reaches? What is the velocity of the ball when it hits the ground (height 0 )?

anonymous · Answer

um not much more than 64 feet, but idk what the actual number is

anonymous · Answer

in those �  it's just your same problem ok all those � are just -

anonymous · Answer

some thing is wrong with my computer, your post says....
in those ????????????????????????????????????????????????????????????????? It's just your same problem ok all those ??????????????????????????????????????????????????????????????????????????? are just-

anonymous · Answer

all those are just 1 - it won't say -

anonymous · Answer

ok, what is it? :)

anonymous · Answer

. A body of mass 400g dropped from a height of 30m. If after rebounce the ball loses 2/3 of its energy, calculate: .the velocity before bounce, .the height after rebounce, .the velocity after rebounce

anonymous · Answer

wait, how to you know it's 400g? Also is 64 feet 30 m?

anonymous · Answer

@trinajoy

anonymous · Answer

i just said it is explains it up there silly lol

anonymous · Answer

oh ok :)

anonymous · Answer

wait is is multiple chocie

anonymous · Answer

no :(

anonymous · Answer

wait am trying to figure this out

anonymous · Answer

it can't be a negative number, my teacher said.  Is there a way to put 19 into the equation to check it?

anonymous · Answer

sorry i can't seem to figure this out :(

anonymous · Answer

I ill try and get someone else to help you :(

anonymous · Answer

k @Ellie202000 do you know how?

anonymous · Answer

@triciaal

anonymous · Answer

@undeadknight26 @welshfella @marylou004 @mathislovemathislife

anonymous · Answer

@Ravenn @whydoihavetosignup1 @kropot72 @BlossomCake @VanBigfoot @XxInfiniteLovexX  @zpupster

anonymous · Answer

anyone here?

zpupster · Answer

h=-16t^2 +48t +64

set h to 0 and solve for t
0 = -t2 + 3t + 4     divide out the 16 

factor and throw out the negative number