A pendulum bob has a speed of 3 m s - 1 at its lowest position. The pendulum is 50 cm long. The speed of bob, when the length makes an angle of 60 ° to the vertical will be g = 10 m s - 2 ______ m s - 1 .

Step-by-step solution

Applying work energy theorem: w g + w T = Δ K - m g l 1 - cos 60 ° = 1 2 m v 2 - 1 2 m u 2 v 2 = u 2 - 2 g l 1 - cos 60 ° v 2 = 9 - 2 × 10 × 0 . 5 1 2 v 2 = 4 v = 2   m   s - 1