Answer: 800 J
Explanation:
Power is the rate between the energy transferred (E) and the time taken (t):
[tex]P=\frac{E}{t}[/tex]
In this problem, the hair straightener has a power of P = 800 W. therefore, the energy transferred in t = 1 second is
[tex]E=Pt=(800 W)(1 s)=800 J[/tex]