Question: A boy is sitting on a swing at a maximum height of 5m above the ground. When the swing passes throug...

Question

A boy is sitting on a swing at a maximum height of 5m above the ground. When the swing passes through the mean position which is 2m above the ground its velocity is approximately

Answer 1

Solution

By the conservation of energy Total energy at point A = Total energy at point B

⇒ $mgh_{1} = mgh_{2} + \frac{1}{2}mv^{2}$

⇒ $9.8 \times 5 = 9.8 \times 2 + \frac{1}{2}v^{2}$

⇒ $v^{2} = 58.8$ ∴ $v = 7.6m/s$