The density of a liquid could be found by using

Can someone explain to me how to do this problem ?

**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

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2