Question

27. A father and his two children are at a playground. There is a see-saw (or teeter-totter) consisting of a uniform six meter long bar pivoted at the center. If an arrangement can be worked out where the father and the children are seated on the see-saw so the sum of all of the torques about the center equal to zero, would the same arrangement of masses on an identical bar result in zero torque on the moon? a. Yes. (b.) No, because the moon has no atmosphere. C. No, because they are now too close to the Sun. d. No, because the moon's gravity is only 1/6 that of Earth's. e. No, because the bar would not be long enough for equilibrium on the moon.

   not sure if this is correct or not.

Answer 1

• Yes.  

Note- because on moon gravity is g/6 which would decrease weight of each person in exact same ratio so when balancing torque would cancel out gravity term from both side . Thus torque balancing of see-saw is independent of gravity of particular planet and could be tested on any planet with exact same arrangement of masses on see-saw.