For convection to occur,
a. dark objects are required to absorb energy.
b. substances must be in contact with each other.
c. particles must be able to flow within a substance.
d. heat must transfer from an area of less energy to more energy.

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?