A person stands on the roof of a building, 40 m high. He throws a rock directly up at 10 m/s. How long until it hits the ground?(adsbygoogle = window.adsbygoogle || []).push({});

I know how to do this in 2 steps: compute height that the rock rises to (~5 meters), then compute time for an object to free fall from 0 m/s to the ground ~45 meters below.

But isn't there a way to do it in one step?

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# Homework Help: Simple kinmatics

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