Question

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

Options

• `("mu"^2sin2theta)/2`

• mu² cos θ

• mu² sin θ

• `("mu"^2costheta)/2`

Answer 1

Average torque on a projectile of mass m, initial speed u and angle of projection θ between initial and final positions P and Q as shown in figure about the point of projection is `bb(("mu"^2sin2theta)/2)`.

Explanation:

Li = 0,

L_f = m × u sin θ × R

∴ ∆L = L_f

Now,

τ_av = `(Delta"L")/(Delta"t") = "L"_"f"/"T"`

= `(mu sin theta  "R")/((2"u"sin theta)/"g")`

= `("mu"^2sin2theta)/2`