physics
posted by kate on .
Two children are balancing on a teetertotter. One child has a mass of 30.0 kg and is sitting 1.3 meters from the pivot. The second child is sitting 0.8 meters from the pivot. What is the mass of the second child

The total moment about the pivot will be zero when there is balance. Write that as an equation and solve for the unknown mass.
Show your work for further assistance, if needed.