Hi all, I had this question in my homework today...

"An electric tea kettle consumes 576.2 kJ of electrical energy while heating a pot of water. By the time the water boils it has gained 381.4 kJ of heat.

a) What is the percent efficiency of the conversion of electrical energy to heat done by the kettle?

b) Why was there less energy absorbed by the water than was supplied by the kettle?"

--

For part A, I used the percent efficiency formula, and calculated the answer at 151%. I'm not sure if this is right...if it isn't, can someone please explain how to get the correct answer?

I'm also unsure as to the answer for part B...

Thanks in advance for any help, much appreciated.