Question : A particle is projected at an angle of 60° above the horizontal with a speed of 10 ms−1 . After some time the direction of its velocity makes an angle of 30° above the horizontal. The speed of the particle at this instant is
(A) \dfrac{5}{\sqrt{3}}ms^{-1}
(B) 5\sqrt{3}ms^{-1}
(C) 5ms^{-1}
(D) \dfrac{10}{\sqrt{3}}ms^{-1}
Answer : option (D)
Solution :
