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#1 2022-07-04 03:34:31

westjadew
Guest

Quadratic equations

Hello,
I need help with this exercise.

A ball is launched upward at a speed of 20 meters per second (m/s) from a 60-meter tall platform.  The equation for the ball’s height (h in meters) at time t seconds after launch is h = -4.9t2 + 20t + 60.   How long before the ball hits the ground?

#2 2022-07-04 19:24:40

Bob
Administrator
Registered: 2010-06-20
Posts: 10,058

Re: Quadratic equations

hi westjadew

Welcome to the forum.

When the ball hits the ground h = 0

So put that value into the quadratic equation and try to find it's two factors.  One will be negative so you can disregard that.  The other is the answer you want.

Bob


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

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