Question

A flea jumps straight up to a maximum height of 0.540 m . what is its initial velocity v0 as it leaves the ground?

Answer 1

For an uniformly accelerated motion, we can write

`2ah=v_f^2-v_0^2`
where
`a=g=-9.81 m/s^2` is the acceleration of this motion, which in this problem is the gravitational acceleration, with a negative sign because it points downward, against the direction of the motion; h=0.540 m is the distance covered by the flea, and
`v_0` is the initial velocity.

At the maximum height, the velocity is zero, so
`v_f =0`. Therefore we can solve to find
`v_0`:

`v_0 = √(2ah)= √(2(9.81 m/s^2)(0.540 m)) =3.25 m/s`