A stone hanging from a massless string of length 15 m is projected horizontally with speed 12 m s - 1 . The speed of the particle, at the point where the tension in the string is equal to the weight of the particle, is close to

Step-by-step solution

u = 12   m   s - 1 T   –   m g   cos ⁡ θ = m v 2 l As, T = m g we get m g 1 - cos θ = m v 2 l Also we know that 1 2 m v 2 - 1 2 m u 2 =   –   m g l l – cos ⁡ θ 1 2 m v 2 - 1 2 m u 2 = - m v 2 ⇒ v = u 3 = 12 3 = 6 . 93   m   s - 1 ≈ 7   m   s - 1