Question

Nicholas sends 20.0 minutes ironing shirts with his 1800-watt irn . How many joules of energy were usedby the iron

Answer 1

1 watt = 1 joule/sec
1800 watts = 1800 joules/sec

                 (1800 J/sec) x (20 min) x (60 sec/min)

             =  (1800 x 20 x 60) joules  =  2,160,000 joules .

                                                             ( 2.16 megajoules )