Atransformer is used to change: 1) power 2) frequency 3) capacitance 4) none of the above

**urgent** roberto plans to use two transformers to reduce a voltage of 120 v to 4 v. he uses a transformer that has 300 coils in the primary winding and 50 coils in the secondary winding. he has four other transformers, as listed in the table. which transformer should roberto use to have an ending voltage of 4 v? a- w b-xc- yd- z

Cathy is pedaling down a steep hill on her bicycle and wants to be able to coast up the next hill, which is 25 meters high, without pedaling. cathy and her bicycle have a mass of 75 kg. assuming her bicycle is 100% efficient, what would her speed have to be?

Assume that two of the electrons at the negative terminal have attached themselves to a nearby neutral atom. there is now a negative ion with a charge -2e at this terminal. what are the electric potential and electric potential energy of the negative ion relative to the electron? the electric potential and the electric potential energy are both twice as much. the electric potential is twice as much and the electric potential energy is the same. the electric potential is the same and the electric potential energy is twice as much. the electric potential and the electric potential energy are both the same. the electric potential is the same and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron. the electric potential is twice as much and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron.