A projectile thrown with an initial speed u and angle of projection 15∘ to the horizontal has a range R. If the same projectile is thrown at an angle of 45∘ to the horizontal with speed 2u, its range will be
Since horizontal range,
R=u2sin2θg
∴ R ∝ u2sin2θ
R2R1=(u2u1)2(sin2θ2sin2θ1)
Given:
u1=u, θ1=15∘, u2=2u, θ2=45∘, R1=R
⇒R2=R1(2uu)2(sin90∘sin30∘)=8R
hence, option (C) is the right choice.