Balancing forces on a modified Seesaw:
Consider the same seesaw (M = 40 kg and length L = 5.0 m), but now the pivot P is at the far end, with a child of m2 = 30 kg sitting a distance r2 = 4.0 m to the left of the pivot. To balance the net torque on the beam, a perpendicular rope that can exert a torque via upwards tension force is attached to the beam at a distance r = 1.0 m from the pivot. Assume the torque from the child and the beam balances the torque from the rope's tension, so that the system is in rotational equilibrium, at rest.
a) Calculate the upward force F (tension in the rope) in terms of M, m2, r2, r, L, and g, and then plug in the values above to find the force F that is needed for equilibrium.
b) Now, consider that the rope tension balancing the torque is at an angle θ = 120°, rather than being vertical. Calculate the new force F' in terms of M, m2, r2, r, L, and g, and then plug in the values above to find the force F' that is needed for equilibrium.