Hi there, I am in college algebra. I haven't done any of this in 3 years and am a bit rusty, I am very far behind and don't understand how to do this! Can someone please not just give me answers but help explain how to do a problem for me? The problem is this...(adsbygoogle = window.adsbygoogle || []).push({});

An object is propelled vertically upward with an initial velocity of 20 meters per second. The distance s(in meters) of the object from the ground after t seconds is s=4.9t^2+20t

a) When will the object be 15 meters above the ground?

b) when will it strike the ground?

c) Will the object reach a height of 100 meters.

I am guessing that with the a) you would make s=15 but as for what to do from there I have no idea. Same for be except making s=0?? And as far as c I don't have a clue. How could you answer c without knowing the rate that the object slows down to know if it would ever make it that high? I just don't get it!

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# Homework Help: Can someone help explain this?

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