Quadratic Formula Help

[iotiX]

I can't seem to find out how they found this answer... it involves the quadratic formula, but i have NO clue how to find the answer.

Problem:
A ball is thrown upward from an initial height of 20 meters at an initial velocity of 10 meters per second. Write an equation for the heigh h of the ball t seconds after being thrown.

Answer: h = -4.9t^2+10t+20

Please show the steps involved , so i can solve problems like this one in the future.

 

[stapel]

I don't see how this involves the quadratic formula, since it's asking you the create a function, not solve an equation.

You should memorize the following, since your course apparently expects you to know this;

. . . . .For initial height h₀ and initial velocity v₀, and with
. . . . .the constant g due to gravity being "-4.9" for "meters"
. . . . .problems and "-16" for "feet" problems, the height s(t)
. . . . .at time t (in seconds) is given by:

. . . . .s(t) = gt² + v₀t + h₀

Plug your values in.

Eliz.

 

[iotiX]

ah. that's rather strange, since the chapter is about the quadratic formula... oh well, thanks for the help.

 

[Denis]

I can't seem to find out how they found this answer... it involves the quadratic formula, but i have NO clue how to find the answer.
Problem:
A ball is thrown upward from an initial height of 20 meters at an initial velocity of 10 meters per second. Write an equation for the heigh h of the ball t seconds after being thrown.
Answer: h = -4.9t^2+10t+20

Of course, -4.9t^2 + 10t + 20 - h = 0 is a quadratic,
and you'd use it to solve for t given h,
but, as Eliz tells you, that's NOT what your problem states.