(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A kangaroo jumps to a vertical height of 2.55 m. How long was it in the air before returning to Earth?

2. Relevant equations

v = v(initial) + a*t

x = x(initial) + v(initial)*t + 1/2*a*t^2

v^2 = v(initial)^2 + 2*a*(x - x(initial))

3. The attempt at a solution

I attempted to use the x = x(initial) + v(initial)*t + 1/2*a*t^2 equation, but it didn't work out. I assumed that x and x(initial) were both 0, since the total displacement is 0, and acceleration would be -9.80 m/s^2. However, I don't know what the velocity would be, and I don't see how I can solve the equation without it.

Any help would be appreciated (sorry about the newbie question, but I just started physics)

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# Homework Help: Basic Vertical Height Problem

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