Hey Guys, here are my questions (with the work included.) Please tell me what I am doing wrong as it is not working on webassign.(adsbygoogle = window.adsbygoogle || []).push({});

A stone is thrown vertically upward with a speed of 15.0 m/s from the edge of a cliff 80.0 m high.

(a) How much later does it reach the bottom of the cliff?

s

(b) What is its speed just before hitting?

m/s

(c) What total distance did it travel?

m

Okay the answer to (c) is 102.9 m (it is the correct answer.)

For A (please open the attached picture if it helps.)

Basically I found the time from when the stone is thrown up to the time when the max height is reached. (velocity = 0) WIth that time, I doubled that to find the time until the 80 m cliff is reached. Then, I found the time it takes for the rock to reach the bottom of the cliff with the equation X= Vi(t) + .5at^2 (a = 9.8; x = 80; Vi = 15 and t = ?)

But unfortunately when I add up the two time measures, they are not working.

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# Homework Help: Basic Kinematics Question(s)

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