**A flea jumps straight up to a maximum height of 0.420 m . What is its initial velocity v0 as it leaves the ground?**

**Answer:**

vf^2=vi^2+1ad

where vf= velocity final vi= velocity initial a= acceleration and d =distance

This is one of the 4 kinematic equations which are very useful for physics

your final velocity is 0 because at the maximum height the object stops moving, depending on your professor or teacher you might use the acceleration of gravity as -9.8 m/s or -9.81 i will use -9.7

0=vi^2-18.6*.420

vi=2.9 m/s