SOLUTION: the height of an object is given by s=-9t^2+vt+s0 where v is the initial velocity and s0 is the initial height. A ball is thrown upward with an initial height of 20 feet and initia

Question 1061168: the height of an object is given by s=-9t^2+vt+s0 where v is the initial velocity and s0 is the initial height. A ball is thrown upward with an initial height of 20 feet and initial velocity of 40 feet per second.
a) after how many seconds does the ball reach its maximum height?
b) what is the maximum height?

Answer by ikleyn(52782)   (Show Source): You can put this solution on YOUR website!
.
the height of an object is given by s=-9t^2+vt+s0 where v is the initial velocity and s0 is the initial height.
A ball is thrown upward with an initial height of 20 feet and initial velocity of 40 feet per second.
a) after how many seconds does the ball reach its maximum height?
b) what is the maximum height?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Hey,

your equation is WRONG.
It is written for "meter" and "meters-per-second" values, while in the condition you use "feet" and "feet-per-second" units.

So, as I see, you are NOT FAMILIAR with such problems at all.

You may want to look into the lessons
    - Problem on a projectile moving vertically up and down
    - Problem on an arrow shot vertically upward
    - Problem on a ball thrown vertically up from the top of a tower
    - Problem on a toy rocket launched vertically up from a tall platform
in this site, where similar problems were solved. Consider them as your samples.

Two lessons are written in "meter" units. Two other are written in "foot" units. Pay special attention to it.

Also, you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic "Projectiles launched/thrown and moving vertically up and dawn".

---------------
Comment from student: This was a problem given by a professor.
---------------

My response:   IT DOESN'T MATTER.         (Actually, it does, of course. But it is even worst).

RELATED QUESTIONS
Foul Ball. Suppose Charlie O'Brian hits a baseball straight upward at 150 ft/sec from a... (answered by stanbon)

The formula h=-16t^2 + v0t +s0 give sthe hieght of an object tossed upward where v0... (answered by ikleyn,johnsss)

the path of a falling object is given by the fuction s=-16t^2+v0t+s0 where v0 represents... (answered by scott8148)

If an object is given an initial velocity of v0 feet per second from a height of S0 feet, (answered by stanbon)

If an object is given an initial velocity of v0 feet per second from a height of S0 feet, (answered by ankor@dixie-net.com)

The path of a falling object is given by the function s=-16t2+v0t+s0 where v0 represents... (answered by scott8148)

The path of a falling object is given by the function s=-16t2+v0t+s0 where v0 represents... (answered by solver91311)

The path of a falling object is given by the function s=-16t^2+v0t+s0 where v0 represents (answered by stanbon)

If an object is given an initial velocity of v0 feet per second from a height of S0 feet, (answered by vleith)