Let's begin by determining the equilibrium position of a seesaw pivot. You and a friend play on a seesaw. Your mass is 90 kgkg, and your friend’s mass is 60 kgkg. The seesaw board is 3.0 mm long and has negligible mass. Where should the pivot be placed so that the seesaw will balance when you sit on the left end and your friend sits on the right end? Let's look at the same scenario we just worked through, but instead the board now has a non-zero mass of 20 kgkg . Where should the pivot be placed for balance?

A tightrope walker is walking between two buildings holding a pole with length ?=15.5 m, and mass ??=19.5 kg. The daredevil grips the pole with each hand a distance ?=0.575 m from the center of the pole. A bird of mass ??=525 g lands on the very end of the left‑hand side of the pole. Assuming the daredevil applies upward forces with the left and right hands in a direction perpendicular to the pole, what magnitude of force ?left and ?right must the left and right hand exert to counteract the torque of the bird?

The uniform seesaw shown below is balanced on a fulcrum located d1 = 3.5m from the left end. The bigger boy on the left end has a mass m1 =75 kg. The smaller boy on the right end has a mass of m2 = 55 kg and is a distance d2 = 4.5 m from the fulcrum. The mass of the board is mb.    Draw all forces acting on the seesaw board showing their directions and locations. Where would you draw the weight of the board? Identify and show the direction of rotations caused by the torques provided by all forces about the fulcrum. If the seesaw is in static equilibrium, write down the two conditions of static equilibrium symbolically using the forces and distances in the figure. Solve for the mass of the board. Calculate the force of fulcrum on the board.

A 50 N weight is located 20 cm from the fulcrum of a balance beam. At what distance from the fulcrum should a 20 N weight be placed to balance the system?

A rider of mass 77.0-kg sits 1.60 meters left of the pivot point.  A different rider sits 3.3 meters to the right of the pivot point. If the see-saw is in equilibrium, what is the rider on the right's mass? The mass of the see-saw is 18.9-kg  Give your answer in kilograms to 3  significant figures (1 decimal place).

Jack and Jill want to balance their seesaw. Where should they set the fulcrum? Jack has a mass of 25 kg, Jill has a mass of 15 kg, and the seesaw board has a mass of 20.0 kg.

A rider of mass 78.0-kg sits 1.70 meters left of the pivot point. A different rider sits 3.5 meters to the right of the pivot point. If the see-saw is in equilibrium, what is the rider on the right's mass? The mass of the see-saw is 19.2-kg Give your answer in kilograms to the correct number of significant figures.