This problem only gives us two givens: the distance and the angle the projectile (in this case a human body) moves. We start by breaking down the initial velocity into its x and y components:
The velocity in the x-direction will remain constant throughout flight, while the velocity in the y direction will be acted upon by gravity.
In the x-direction the accleration is zero and the distance moved is d, the length of the jump, so:
In the y direction the acceleration is g and the distance moved is zero because you leave the ground and return to it at the end of the jump:
At the beginning we found expressions for the component velocities of the initial velocity, and we replace 
and 
with their respective expressions now:
We take the first equation and solve for t
We now plug in this expression for t into the equation above and solve for the initial velocity
