- #1
Eternal Sky
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Homework Statement
A kangaroo jumps to a vertical height of 2.55 m. How long was it in the air before returning to Earth?
Homework 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))
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)