Answer:

Step-by-step explanation:
The range of a projectile is given by the formula

where in this case, we have
d = 100 m is the range
u is the initial speed (the magnitude of the initial velocity)
g = 9.8 m/s^2 is the acceleration of gravity
is the angle of projection
Solving for u, we find:

Now we can easily find the components of the initial velocity:

So, the initial velocity of the ball is

where i and j are the unit vector indicating the horizontal and vertical direction.