In the locus diagrams of two projectiles I and 2 as shown in the fig.,
T1>T2 and v01 < v02
T1 = T2 and v01< v02
T1 = T2 and v01 > v02
T1 < T2 and v01 < v02
Both projectiles have same height.
∴ H1 = H2
(u1sin θ1)22g = (u2sinθ2)22g
u1sin θ1 = u2sin θ2
2u1sin θ1g = 2u2sin θ2g ⇒ T1 = T2
Now u1u2 = sin θ2sin θ1 sin θ1 > θ2
sin θ1sin θ2 > 1 ⇒ u1u2 <1