Hi, i'm new to the forum so i don't really quite know what i'm doing yet! anyway, i know this question is REALLY basic but physics is not my forte and i'm confused... "John has just bought a new iron and sees this plate on the handle - 230V 1840W 50Hz" John irons a shirt for 10s energy transformed = power x time so if i'm correct: time = 10s power= 1840W energy transformed = 18400J the final question "John can tell from the plate that the iron can operate using mains supply. How can he tell this?" and i have absolutely no idea! help would be greatly appreciated - i really need to understand this, its from a gcse mock paper and my exam is in a couple of weeks!