Number 4 part a initial velocity and part b maximum height show all work

Minimum speed does he require if he lands at the initial level: 4) A projectile fired from the ground has a velocity v = 24.0i - 8.00 j m/s at a height of 9.10 m. Find: (a) the initial velocity; (b) the maximum height. 5) sprinter runn magnitude 9.20 m/s and a