A particle of mass m , initial speed u and angle of projection θ , is projected as shown in the figure. Average torque on the projectile between initial and final positions P and Q about the point of projection is

Step-by-step solution

τ → α v × Δ t =Δ L → ...(1) Here, Δ t = time of flight = 2 u sin θ g Δ → L = L → f - L → i about the point of projection. = m u sin θ range - 0 = m u sin θ u 2 sin 2 θ g ∴ τ → a v = Δ L Δ t = m u 3 sin θ sin 2 θ g g 2 u sin θ = m u 2 sin 2 θ 2