Three children are riding on the edge of a merry‑go‑round that has a mass of 105 kg and a radius of 1.60 m. The merry‑go‑round is spinning at 24.0 rpm. The children have masses of 22.0, 28.0, and 33.0 kg. What is the equation of the total moment of inertia? Ignore friction, and assume that the merry‑go‑round can be treated as a solid disk and the children as point masses.

Point charges q1=+2.00μc and q2=−2.00μc are placed at adjacent corners of a square for which the length of each side is 1.50 cm . point a is at the center of the square, and point b is at the empty corner closest to q2. take the electric potential to be zero at a distance far from both charges. part a what is the electric potential at point a due to q1 and q2? express your answer with the appropriate units.