Question

Two projectiles are fired at the angles of 30' and 60'. The product of their time of fight is
approximately equal to: :
a) R/g
b) 2Rmax./g
c) 3Rmax/g
d) 4R/g​

Answer 1

:

b) 2R/g

Explanation:

T1 = 2u sin 30°/g

T2 = 2u sin 60°/g

so, T1×T2 = 4u^2 sin 30° × sin (90-30)/g^2

= 4u^2 sin 30° × cos 30°/g^2

= 2Rmax/g