Why would you not be able to hear a sound in space?

For waves in the ocean, the medium of the waves is a. air b. water c. energy d. a passing boat

Atoaster oven has a resistive heating element. the average rate at which it dissipates energy as thermal energy is 1.00 \(\rm kw\). in the united states, emf amplitude in household circuits is \(\mathcal e_{\max}\) = 170 \({\rm \; v}\) and the \(\rm ac\) oscillation rate is 60 \(\rm hz\). part a what is the root-mean-square current through the heating element?

Is a copper wire a conductor or insulator?