How can a Mechanical PE transform one form to another form?

If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?

Which compound contain an iron with a 3+ charge

The twister and runaway train are two coasters at the same amusement park. both coasters start at the same height. the coaster for the twister is twice the mass of the coaster for the runaway train. which roller coaster has greater gravitational potential energy at the start of the ride?