Five balls A,B,C,D and E are projected with the same speed making angles of 10o, 30o, 45o, 60o and 80o respectively with the horizontal. Which ball will strike the ground at the farthest point?

The horizontal range of a projectile is given byR=u2sin⁡2θgThe range R is maximum when sin⁡2θ is maximum. Thussin⁡2θ=1    or    2θ=π/2or     θ=π/4∴   θ=45∘So, the body C will have the maximum range.