Question : A projectile is thrown with a speed 𝑢 at an angle θ to the horizontal. The radius of curvature of its trajectory when the velocity vector of the projectile makes an angle α with the horizontal is
(A) \dfrac{u^{2}\cos ^{2}\alpha }{g\cos ^{2}\theta }
(B) 2 \dfrac{u^{2}\cos ^{2}\alpha }{g\cos ^{2}\theta }
(C) \dfrac{u^{2}\cos ^{2}\theta }{g\cos ^{3}\alpha }
(D) \dfrac{u^{2}\cos ^{2}\theta }{g\cos ^{2}\alpha }
Answer : option (C)
Solution :
