A lead fishing weight of mass 0.2 kg is tied to a fishing line that is 0.5 m long. the weight is then whirled in a vertical circle. the fishing line will break if its tension exceeds 60 n.

In the movement of the weight in vertical circle, using momentum balance, the largest tension is at the bottom of the circle. This is represented by:

F = T - m g

T = F + m g

F (centripetal) = mv^2/r

= m v^2 / r + m g

m v^2 / r = T - m g

T = 0.5m * 100kgm/s^2 / 0.2kg - 9.81m/s^2 * 0.5m

T = 245 m^2/s^2