- #1

Natko

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## Homework Statement

An object thrown up from a cliff 10 m/s reaches a velocity of 20 m/s [down] as it lands. If acceleration due to gravity is 9.8 m/s

^{2}, what is the

__object's displacement__?

__How long did it take__for the object to land from the time it was thrown?

## Homework Equations

I'm not sure if all of the below are relevant, or perhaps some equations are missing.

Δx = v

_{0}t + 1/2at

^{2}

(displacement = initial velocity x time + 1/2 acceleration x time squared)

v

_{f}

^{2}= v

_{0}

^{2}+ 2aΔx

(final velocity squared = initial velocity squared + 2 acceleration x displacement

## The Attempt at a Solution

t

_{1}= v/a = 1.02 s

t

_{2}= v/a = 2.04 s

t

_{1}+ t

_{2}= 3.1 s

Not sure how to find the displacement, but the answer key says it's -15m. How do I find it?