Question

A 45.7-kg boy on a swing moves in a circular arc of radius 3.80 m.At the lowest position, the child's speed reaches 2.78 m/s. Determine the magnitude of the tension in each of the two vertical support chains

Answer 1

If he sits in the middle of the swing, the tension force on each support chain will be equal. Call it T.

At the lowest position,
2T - weight = centripetal force
= M V^2/R.

2T = M*(g + V^2/R)

Solve for T.

M = 45.7 kg
R = 3.80 m
V = 2.78 m/s
g = 9.80 m/s^2

Answer 2

2.7