Some enterprising physics students working
on a catapult decide to have a water balloon
ﬁght in the school hallway. The ceiling is of
height 3.3 m, and the balloons are launched
at a velocity of 9.7 m/s. The acceleration of gravity is 9.8 m/s2 .At what angle must they be launched to just graze the ceiling?Answer in units of ◦
Im not quiet sure which equation to use, all of projectile motion is really tough for me.