Given,
Power consumed by the clothes iron, P=500 W
The time period during which the iron was operated, t=30 mins= 0.5 hours.
Cos of electricity per kWh, C=0.120 $
The energy consumed by the iron can be calculated as,
[tex]E=P\times t[/tex]On substituting the values,
[tex]E=500\times0.5=250\text{ Wh}=0.250\text{ kWh}[/tex]Therefore the cost of the electricity can be calculated as,
[tex]\text{Total cost=C}\times E[/tex]On substituting the known values,
[tex]\text{Total cost=0.120}\times0.250=0.03\text{ \$}[/tex]Therefore the total cost of the electricity used by the iron is 0.03 $
